Product Description AUZGRIP 6pc Noid Light Set A20075 These handy Noid light sets are the most economical way to check electronic fuel injection electrical signals. Simple to use the lights are used by simply disconnecting the fuel injectors, pluggingthe Noid Light into the injector wiring harness. When the engine is cranked, normal signals are indicated by rapid flashes on Noid Light. A constant light or no light at all confirms EFI signal problem. Packed in a convenient blow molded storage case these kits will save you time and effort when working on injection systems Features Use the Light set to check Bosch PFI, GM PFI, GM TBI, GM SCPI, Ford TBI, and the Geo TBI systems Professional grade Molded case for storage