{"product_id":"proton-4-in-1-digital-cylinder-diagnostic-system","title":"PROTON Cylinder Gauge (4-in-1 Digital Diagnostic System)","description":"\u003cstyle\u003e\n.alp-pdp{color:#ececec;}\n.alp-pdp h2,.alp-pdp h3{color:#ffffff;}\n.alp-pdp h3{margin-top:34px;margin-bottom:6px;}\n.alp-pdp p{margin:12px 0;}\n.alp-pdp a{color:#ff5a4d;}\n.alp-pdp ul{margin:16px 0 22px;padding-left:22px;}\n.alp-pdp li{margin-bottom:14px;line-height:1.55;}\n.alp-pdp .sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0;}\n.alp-pdp table{width:100%;border-collapse:collapse;margin:16px 0 28px;font-size:14px;}\n.alp-pdp .spec th{text-align:left;padding:13px 16px;background:#1a1a1a !important;color:#ffffff !important;border-bottom:3px solid #E10600;}\n.alp-pdp .spec td{padding:12px 16px;border-bottom:1px solid rgba(255,255,255,0.12) !important;background:#121212 !important;color:#ececec !important;}\n.alp-pdp .spec td:first-child{font-weight:600;color:#ffffff !important;width:42%;}\n.alp-pdp .spec tbody tr:nth-child(even) td{background:#1b1b1b !important;}\n.alp-pdp .cmp-block{margin:24px 0 34px;}\n.alp-pdp .cmp-title{font-size:18px;font-weight:700;color:#ffffff;margin:0 0 4px;}\n.alp-pdp .cmp-sub{font-size:13px;color:rgba(255,255,255,0.55);margin:0 0 10px;}\n.alp-pdp .cmp{table-layout:fixed;}\n.alp-pdp .cmp th,.alp-pdp .cmp td{padding:12px 14px;border-bottom:1px solid rgba(255,255,255,0.12) !important;vertical-align:middle;background:#121212 !important;color:#ececec !important;}\n.alp-pdp .cmp thead th{font-size:12px;text-transform:uppercase;letter-spacing:0.06em;color:rgba(255,255,255,0.6) !important;}\n.alp-pdp .cmp th:nth-child(1),.alp-pdp .cmp td:nth-child(1){width:50%;text-align:left;color:#ffffff !important;font-weight:600;}\n.alp-pdp .cmp th:nth-child(2),.alp-pdp .cmp td:nth-child(2){width:25%;text-align:center;}\n.alp-pdp .cmp th:nth-child(3),.alp-pdp .cmp td:nth-child(3){width:25%;text-align:center;}\n.alp-pdp .cmp td.hs{background:#3a0f0f !important;}\n.alp-pdp .cmp thead th.hs{background:#E10600 !important;color:#ffffff !important;}\n.alp-pdp .chk{display:inline-flex;align-items:center;justify-content:center;width:22px;height:22px;border-radius:999px;font-size:12px;font-weight:800;line-height:1;}\n.alp-pdp .chk-solid{background:#E10600;color:#ffffff;}\n.alp-pdp .chk-muted{border:1px solid rgba(255,255,255,0.3);color:rgba(255,255,255,0.4);}\n.alp-pdp .dash{color:rgba(255,255,255,0.4);font-weight:800;}\n.alp-pdp .muted{color:rgba(255,255,255,0.65) !important;font-size:13px;}\n.alp-pdp .strong{font-weight:700;color:#ffffff !important;}\n.alp-pdp .stack{display:inline-flex;flex-direction:column;align-items:center;gap:4px;}\n.alp-pdp .subtext{font-size:12px;color:rgba(255,255,255,0.6) !important;line-height:1.2;text-align:center;}\n.alp-pdp .legend{display:flex;gap:14px;flex-wrap:wrap;align-items:center;font-size:12px;color:rgba(255,255,255,0.55);margin:0 0 14px;}\n.alp-pdp .legend-item{display:inline-flex;gap:6px;align-items:center;}\n.alp-pdp .footnote{font-size:12px;color:rgba(255,255,255,0.5);margin:8px 0 18px;}\n.alp-pdp .disclaimer{font-size:13px;color:rgba(255,255,255,0.5);}\n@media (max-width:600px){\n.alp-pdp table{font-size:12px;}\n.alp-pdp .muted{font-size:12px;}\n.alp-pdp .spec th,.alp-pdp .spec td{padding:9px 10px;}\n.alp-pdp .spec td:first-child{width:44%;}\n.alp-pdp .cmp th,.alp-pdp .cmp td{padding:9px 6px;}\n.alp-pdp .cmp th:nth-child(1),.alp-pdp .cmp td:nth-child(1){width:42%;}\n.alp-pdp .cmp th:nth-child(2),.alp-pdp .cmp td:nth-child(2){width:29%;}\n.alp-pdp .cmp th:nth-child(3),.alp-pdp .cmp td:nth-child(3){width:29%;}\n.alp-pdp .cmp thead th{font-size:11px;letter-spacing:0.01em;}\n.alp-pdp .subtext{font-size:11px;}\n.alp-pdp .chk{width:20px;height:20px;font-size:11px;}\n.alp-pdp .legend{flex-direction:row;flex-wrap:nowrap;justify-content:space-between;align-items:flex-start;gap:8px;}\n.alp-pdp .legend-item{flex-direction:column;align-items:center;text-align:center;gap:4px;flex:1 1 0;font-size:11px;line-height:1.25;}\n}\n@media (max-width:400px){\n.alp-pdp table{font-size:11px;}\n.alp-pdp .muted{font-size:11px;}\n.alp-pdp .spec th,.alp-pdp .spec td{padding:8px 8px;}\n.alp-pdp .cmp th,.alp-pdp .cmp td{padding:8px 5px;}\n}\n\u003c\/style\u003e\n\u003cdiv class=\"alp-pdp\"\u003e\n\u003ch2\u003ePROTON Cylinder Gauge (4-in-1 Digital Diagnostic System)\u003c\/h2\u003e\n\n\u003cp\u003e\u003cstrong\u003eThe Proton replaces four separate engine-diagnostic tools with one touchscreen unit — a digital compression tester, a cylinder leak-down tester, a pressure \u0026amp; vacuum gauge, and a top dead center (TDC) assistant.\u003c\/strong\u003e Every reading is logged automatically to the cylinder it came from, and the leak-down percentage is calculated for you the moment you dial in 100 PSI — no notepad, no dividing one analog gauge by another. A single chart screen puts every cylinder side by side so a weak one is obvious at a glance. Built for gasoline engines up to 8 cylinders, with multiple spark-plug adapters and quick-connect fittings included, and backed by a 5-year 100% full-coverage warranty with USA-based replacement.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eBest for:\u003c\/strong\u003e independent repair shops and professional technicians running compression and leak-down as part of routine diagnosis; mobile mechanics who need one compact kit instead of four; engine builders and performance shops verifying cylinder sealing; and serious DIY mechanics chasing a misfire, a burnt valve, or a suspected head gasket.\u003c\/p\u003e\n\n\u003ch3\u003eWhat it diagnoses\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eWorn or broken piston rings\u003c\/strong\u003e — low compression plus air escaping into the crankcase.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBurnt or leaking valves\u003c\/strong\u003e — air escaping out the intake (intake valve) or the exhaust (exhaust valve).\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBlown head gaskets\u003c\/strong\u003e — two adjacent cylinders down together, bubbles in the coolant, or air crossing into the next cylinder.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePoor cylinder sealing\u003c\/strong\u003e — scored bores, carbon on a valve seat, anything that costs a cylinder its seal.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eVacuum and timing problems\u003c\/strong\u003e — low or unsteady manifold vacuum, restricted exhaust, and general vacuum leaks.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eFour tests, one unit\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eDigital compression test\u003c\/strong\u003e — thread the hose into a spark-plug hole, select the cylinder on screen, and crank. The peak reading is captured and logged to that cylinder automatically.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCylinder leak-down test\u003c\/strong\u003e — feed the sealed cylinder 100 PSI of shop air and the Proton calculates and displays the leak percentage. Where you hear the air escaping tells you which part failed.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePressure \u0026amp; vacuum gauge\u003c\/strong\u003e — read manifold vacuum on a running engine in inHg, kPa or PSI, with high and low modes and a live graph-over-time view that shows whether vacuum is steady or oscillating.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTop dead center (TDC) assistant\u003c\/strong\u003e — find TDC by watching pressure and vacuum as you turn the crankshaft, instead of guessing with a screwdriver or hunting timing marks. Accurate TDC is what makes a leak-down number mean anything.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eSpecifications\u003c\/h3\u003e\n\u003ctable class=\"spec\"\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eFeature\u003c\/th\u003e\n\u003cth\u003eDetail\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eTests performed\u003c\/td\u003e\n\u003ctd\u003eCompression · Cylinder leak-down · Pressure \u0026amp; vacuum · TDC location\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDisplay\u003c\/td\u003e\n\u003ctd\u003eDigital touchscreen with on-screen test shortcuts and instructions\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSensors\u003c\/td\u003e\n\u003ctd\u003eDigital pressure and vacuum sensors for repeatable readings\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eData logging\u003c\/td\u003e\n\u003ctd\u003eAutomatic per cylinder; chart view compares all cylinders on one screen\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eLeak-down calculation\u003c\/td\u003e\n\u003ctd\u003eAutomatic leak % at a 100 PSI reference input — no manual math\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eVacuum units\u003c\/td\u003e\n\u003ctd\u003einHg, kPa or PSI, switchable on the display\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eVacuum modes\u003c\/td\u003e\n\u003ctd\u003eHigh \/ low range, plus live graph-over-time\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCylinders supported\u003c\/td\u003e\n\u003ctd\u003eUp to 8 cylinders, each logged and compared separately\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eEngine compatibility\u003c\/td\u003e\n\u003ctd\u003eGasoline engines. \u003cspan class=\"strong\"\u003eNot for diesel engines.\u003c\/span\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAdapters\u003c\/td\u003e\n\u003ctd\u003eMultiple spark-plug adapters and quick-connect fittings included\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAlso required\u003c\/td\u003e\n\u003ctd\u003eRatchet to turn the crankshaft (TDC \/ leak-down) · air compressor at 100 PSI (leak-down only)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eShipped weight \u0026amp; package\u003c\/td\u003e\n\u003ctd\u003e4 lb · 15.5 × 11 × 2 in\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWarranty\u003c\/td\u003e\n\u003ctd\u003e5-year 100% full coverage — manufacturer and operational defects, USA-based fast replacement\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch3\u003eWhat's in the box\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eProton digital cylinder gauge, with the one-way valve and plunger (bleed) valve on the unit\u003c\/li\u003e\n\u003cli\u003eCylinder hose that threads into the spark-plug hole\u003c\/li\u003e\n\u003cli\u003eExtension hose for hard-to-reach cylinders\u003c\/li\u003e\n\u003cli\u003eEngine cylinder adapters for a range of spark-plug threads and reaches\u003c\/li\u003e\n\u003cli\u003eQuick-connect fittings and accessories\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWho it's for\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eRepair shops and professional technicians.\u003c\/strong\u003e Compression and leak-down are routine work, and the time cost is usually in the record-keeping, not the testing. Automatic per-cylinder logging and a single comparison screen cut the paperwork out of the job and make the result easier to show a customer.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eMobile mechanics.\u003c\/strong\u003e One compact case does the work of a compression tester, a leak-down tester, a vacuum gauge, and whatever you were using to find TDC.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eEngine builders and performance shops.\u003c\/strong\u003e Leak percentage calculated to the same 100 PSI reference every time makes cylinder-to-cylinder and before\/after comparisons meaningful.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDIY mechanics.\u003c\/strong\u003e If you're chasing a misfire, a rough idle, or a suspected head gasket, this tells you which cylinder is down and then which component is letting go — the two questions that decide whether an engine comes apart.\u003c\/p\u003e\n\n\u003ch3\u003eDigital vs. a traditional analog setup\u003c\/h3\u003e\n\u003cdiv class=\"cmp-block\"\u003e\n\u003cp class=\"cmp-title\"\u003eRunning the tests\u003c\/p\u003e\n\u003cp class=\"cmp-sub\"\u003eProton compared with a conventional analog compression gauge plus a separate dual-gauge leak-down tester.\u003c\/p\u003e\n\u003cdiv class=\"legend\"\u003e\n\u003cspan class=\"legend-item\"\u003e\u003cspan class=\"chk chk-solid\" aria-hidden=\"true\"\u003e✓\u003c\/span\u003e Included\u003c\/span\u003e\n\u003cspan class=\"legend-item\"\u003e\u003cspan class=\"chk chk-muted\" aria-hidden=\"true\"\u003e✓\u003c\/span\u003e Available\u003c\/span\u003e\n\u003cspan class=\"legend-item\"\u003e\u003cspan class=\"dash\" aria-hidden=\"true\"\u003e—\u003c\/span\u003e Not available\u003c\/span\u003e\n\u003c\/div\u003e\n\u003ctable class=\"cmp\"\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eCapability\u003c\/th\u003e\n\u003cth class=\"hs\"\u003ePROTON Cylinder Gauge\u003c\/th\u003e\n\u003cth\u003eAnalog compression + leak-down kit\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eCompression testing\u003c\/td\u003e\n\u003ctd class=\"hs\"\u003e\n\u003cspan class=\"chk chk-solid\" aria-hidden=\"true\"\u003e✓\u003c\/span\u003e\u003cspan class=\"sr-only\"\u003eYes\u003c\/span\u003e\n\u003c\/td\u003e\n\u003ctd\u003e\n\u003cspan class=\"chk chk-muted\" aria-hidden=\"true\"\u003e✓\u003c\/span\u003e\u003cspan class=\"sr-only\"\u003eYes\u003c\/span\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCylinder leak-down testing\u003c\/td\u003e\n\u003ctd class=\"hs\"\u003e\n\u003cspan class=\"chk chk-solid\" aria-hidden=\"true\"\u003e✓\u003c\/span\u003e\u003cspan class=\"sr-only\"\u003eYes\u003c\/span\u003e\n\u003c\/td\u003e\n\u003ctd\u003e\n\u003cspan class=\"chk chk-muted\" aria-hidden=\"true\"\u003e✓\u003c\/span\u003e\u003cspan class=\"sr-only\"\u003eYes\u003c\/span\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eLeak % calculated for you\u003c\/td\u003e\n\u003ctd class=\"hs\"\u003e\u003cspan class=\"stack\"\u003e\u003cspan class=\"chk chk-solid\" aria-hidden=\"true\"\u003e✓\u003c\/span\u003e\u003cspan class=\"sr-only\"\u003eYes\u003c\/span\u003e\u003cspan class=\"subtext\"\u003eAutomatic at 100 PSI\u003c\/span\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan class=\"stack\"\u003e\u003cspan class=\"dash\" aria-hidden=\"true\"\u003e—\u003c\/span\u003e\u003cspan class=\"sr-only\"\u003eNo\u003c\/span\u003e\u003cspan class=\"subtext\"\u003eYou do the math\u003c\/span\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eReadings logged per cylinder\u003c\/td\u003e\n\u003ctd class=\"hs\"\u003e\u003cspan class=\"stack\"\u003e\u003cspan class=\"chk chk-solid\" aria-hidden=\"true\"\u003e✓\u003c\/span\u003e\u003cspan class=\"sr-only\"\u003eYes\u003c\/span\u003e\u003cspan class=\"subtext\"\u003eAutomatic\u003c\/span\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan class=\"stack\"\u003e\u003cspan class=\"dash\" aria-hidden=\"true\"\u003e—\u003c\/span\u003e\u003cspan class=\"sr-only\"\u003eNo\u003c\/span\u003e\u003cspan class=\"subtext\"\u003ePen and paper\u003c\/span\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAll cylinders compared on one screen\u003c\/td\u003e\n\u003ctd class=\"hs\"\u003e\n\u003cspan class=\"chk chk-solid\" aria-hidden=\"true\"\u003e✓\u003c\/span\u003e\u003cspan class=\"sr-only\"\u003eYes\u003c\/span\u003e\n\u003c\/td\u003e\n\u003ctd\u003e\n\u003cspan class=\"dash\" aria-hidden=\"true\"\u003e—\u003c\/span\u003e\u003cspan class=\"sr-only\"\u003eNo\u003c\/span\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eManifold vacuum testing\u003c\/td\u003e\n\u003ctd class=\"hs\"\u003e\u003cspan class=\"stack\"\u003e\u003cspan class=\"chk chk-solid\" aria-hidden=\"true\"\u003e✓\u003c\/span\u003e\u003cspan class=\"sr-only\"\u003eYes\u003c\/span\u003e\u003cspan class=\"subtext\"\u003eLive graph over time\u003c\/span\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan class=\"stack\"\u003e\u003cspan class=\"dash\" aria-hidden=\"true\"\u003e—\u003c\/span\u003e\u003cspan class=\"sr-only\"\u003eNo\u003c\/span\u003e\u003cspan class=\"subtext\"\u003eSeparate gauge needed\u003c\/span\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTDC location assistance\u003c\/td\u003e\n\u003ctd class=\"hs\"\u003e\u003cspan class=\"stack\"\u003e\u003cspan class=\"chk chk-solid\" aria-hidden=\"true\"\u003e✓\u003c\/span\u003e\u003cspan class=\"sr-only\"\u003eYes\u003c\/span\u003e\u003cspan class=\"subtext\"\u003eBy pressure \u0026amp; vacuum\u003c\/span\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan class=\"stack\"\u003e\u003cspan class=\"dash\" aria-hidden=\"true\"\u003e—\u003c\/span\u003e\u003cspan class=\"sr-only\"\u003eNo\u003c\/span\u003e\u003cspan class=\"subtext\"\u003eScrewdriver \/ timing marks\u003c\/span\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSwitchable units (inHg \/ kPa \/ PSI)\u003c\/td\u003e\n\u003ctd class=\"hs\"\u003e\n\u003cspan class=\"chk chk-solid\" aria-hidden=\"true\"\u003e✓\u003c\/span\u003e\u003cspan class=\"sr-only\"\u003eYes\u003c\/span\u003e\n\u003c\/td\u003e\n\u003ctd\u003e\n\u003cspan class=\"dash\" aria-hidden=\"true\"\u003e—\u003c\/span\u003e\u003cspan class=\"sr-only\"\u003eNo\u003c\/span\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTools to buy and carry\u003c\/td\u003e\n\u003ctd class=\"hs\"\u003e\u003cspan class=\"stack\"\u003e\u003cspan class=\"strong\"\u003eOne\u003c\/span\u003e\u003cspan class=\"subtext\"\u003eSingle case\u003c\/span\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan class=\"stack\"\u003e\u003cspan class=\"strong\"\u003eThree or four\u003c\/span\u003e\u003cspan class=\"subtext\"\u003ePlus a way to find TDC\u003c\/span\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003cp class=\"footnote\"\u003eAnalog kits are proven, inexpensive, and need no charging — if you run a compression test twice a year, one is hard to beat on price. The Proton earns its place when you test often enough that the logging, the automatic leak math, and having one kit instead of four save real time.\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003ch3\u003eWarranty and support\u003c\/h3\u003e\n\u003cp\u003eEvery Proton is covered by a \u003cstrong\u003e5-year 100% full-coverage warranty\u003c\/strong\u003e against manufacturer and operational defects. AutoLine Pro is an American family-owned business, and support is USA-based — if a unit fails, we replace it, fast. Questions before you buy? Reach us through the \u003ca href=\"https:\/\/www.autolinepro.com\/pages\/contact-us\"\u003econtact form\u003c\/a\u003e.\u003c\/p\u003e\n\n\u003cp class=\"disclaimer\"\u003eThe Proton is designed for gasoline engines. Diesel compression testing requires higher-range gauges and injector or glow-plug-port adapters, and is not supported by this tool.\u003c\/p\u003e\n\u003c\/div\u003e\n","brand":"AutoLine Pro","offers":[{"title":"Default Title","offer_id":44575498371161,"sku":"APA-PROT","price":199.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0056\/7721\/9929\/files\/proton-cylinder-gauge-4-in-1-digital-diagnostic-system-engine-cylinder-compression-leak-down-tester-autoline-pro-627149.jpg?v=1787610961","url":"https:\/\/www.autolinepro.com\/products\/proton-4-in-1-digital-cylinder-diagnostic-system","provider":"AutoLine Pro","version":"1.0","type":"link"}