Insert the Flexible whistle alert into any spark plug hole and bump the engine until you hear the whistle blow. You are now on the Compression Stroke! Easily finds top dead center on compression stroke - qui. Side release valve allows quick re-testing of cylinder without removing adapter. The 2-1/2 in. gauge has a dual scale dial with ranges from 0 - 300 PSI and 0 - 21 bar. Neatly arranged in a plastic box
Instructions and specifications included. Precise fit and function for today's vehicles Prestone: Protection inside and out. Prestone premium radiator and heater hoses are designed to meet OEM specifications and provide the best fit and function for direct replacement of your vehicle's original equipment.

Tests compression on domestic and imported cars and trucks with gasoline engines. Adapters included: 14mm & 18mm short solid adapter, 14mm & 18mm long flex adapter, and 14mm long reach adapter. 10mm & 12mm adapters available separately. Screw-in adapters with o-rings provide professional accuracy
Long flex 12 hose and adapters eliminate need to remove engine accessories to test compression. Keep the dust where it belongs with this wire-reinforced vinyl hose. It's strong, durable, and flexible enough to easily position where you want it. Best of all, this hose will not collapse, even under heavy suction. Ground your collection system with the wire at either end of the hose.