An alternative to conventional compression testers, which provides a direct indication to the location of the leak by measuring the rate of loss of compression for individual cylinders Helps to diagnose worn / broken piston rings, burnt / leaking valves and faulty head gaskets Supplied with M12 and M14 brass quick release spark plug adaptors to suit most modern petrol cars Adaptors from petrol compression kits and diesel common rail kits are also compatible with the cylinder leakage tester