Will flush and back flush injectors for best possible cleaning process Push button switch to turn fuel injector on with LED indicator light Kit includes fuel injector cleaner tool, pigtail and 9V battery Durable anodized billet aluminum construction Built tough for everyday shop use Easily clean most fuel injectors No compressed air required For best results use Motion Pro fuel injector cleaner part # 3704-0389, it's specifically formulated not to harm O-rings and other fuel injector moving parts (sold separately).. FUEL INJ CLEAN KT HAR EV1