Comes with a 15in. braided stainless steel spark plug hose assembly. Helps detect worn rings, burnt or sticking valves, carbon buildup and more. Designed to work on conventional, electronic and computerized systems on both foreign and domestic vehicles. Large, easy-to-read 2 1/2in. dial face with accurate Bourdon tube meter movement. Dual-calibrated scales read 0-300 PSI. Side-pressure relief valve and quick-connect/disconnect coupler attached. Oil-resistant 15in. flexible rubber hose with 14 and 18mm adapters. Not designed to work in diesel engines, only on spark-ignited gasoline engines where cylinder pressure does not exceed 300 PSI. Also includes 14mm long-reach adapter and 12mm adapter for most snowmobiles, motorcycles, ATVs and marine applications.