TACHOMETER—- Messuring and records your engine RPMs (0-25000RPM); Recording and recall engine MAX RPM. WORKING SIGNAL DETECTION—- One pick-up wire with alligator clip(68.8 inches,workable whatever shorten or extend) installation with spark plug for instant engine signal detection. WATER/SHOCK RESIST—- 100% epoxy resin sealing craft can be kept it away from the damp or moist; INSTALLATION—- Easy to mount it by screw-on at any proper place. OTHERS—- Built-in CR2450 battery with lifetime up 3 years; Reliable technical support and after-sales service(2 years). Product Features: RPM Record real-time RPM value when engine is on, measurement range 0-25000RPM with 10 RPM resolution. Suitable for gas engine 2 stroke up to 3 cylinders, 4 stroke up to 16 cylinders. Display the highest RPM hit since the engine started. Specification: Internal replaceable CR2450 battery. LCD window size:approx.1.06??0.62 inches Product size:approx.2.24×1.41×0.68 inches Accesso