Designed to allow the user to electronically switch a petrol fuel injector, do a full function test as well as aid injector cleaning by combining with a suitable carburettor cleaning fluid. The Laser 8374 is designed to be powered by a 12V battery but can be switched to output 5V or 12V depending on the injector being tested/activated. This allows the unit to be used on standard EFI injectors (12V) as well as GDi injectors (5v).