DC12V 4 Pulse Modes Handheld Ignition Fuel Injector Tester can help diagnose injector problems, you can use it to test each injector individually to help identify stuck, leaking or burnt-out conditions. It uses 12V vehicle battery for power. It has 4 pulse modes, the continuous mode (mode 4) helps identify good or bad injector. The mode lock feature ensures test condition uniformity. It can work with any fuel pressure tester.