Used to inject compressor oil into vehicle AC systems, this kit comes with one cartridge of PAG oil and a PAG oil injector adapter hose. The injector gun is universal and can also be used with POE oil cartridges (sold separately) and the GM-48997 POE Oil Adapter Hose (sold separately) when servicing hybrid or electric vehicle AC systems. The PAG oil and adapter hose in this kit should never be used when servicing a POE oil AC system in a hybrid or electric vehicle.