WITH 4 PULSE MODES, WITH CONTINUOUS WORKING MODE (MODE 4); WORKS WITH ENGINE OFF AND PULSE TIMER MAY BE USED WITH FUEL PRESSURE GAUGE; DIAGNOSE INJECTOR PROBLEMS, YOU CAN USE IT ON EACH INJECTOR INDIVIDUALLY TO TEST STUCK, LEAKING OR BURNT-OUT USED 12V VEHICLE BATTERY AS POWER SUPPLY; IT CAN WORK WITH ANY FUEL PRESSURE TESTER; FOR GASOLINE CAR ONLY, NOT FOR DIESEL ENGINE