This professional gasoline & diesel engine leakage tester is used to quickly and accurately diagnose failed or leaking valves, pistons rings and head gaskets. Connect this kit to the compressed air system and open the adjusting valve slowly until the pointer reaches the 0-mark! Then the air is allowed to escape into the cylinder. Thus the exact cause of leakage can be located by the compressed air flowing thanks to the quite accurate acoustic. This pressure loss tester kit comes with a large easy-to-read dual scale gauge (psi / bar) reading from 0-100 psi and 0-20 bar. All tools are neatly packed in a sturdy case for easy transportation and organized storage.