Professional Assistant Used to remove and install coils in live systems. Quick and easy replacement of leaking coils. Dual size for R410a or R22 charging systems or other retrofit replacement systems. Excellent Workmanship: Valve core remover installation tool is made of solid brass, which is durable and not easy to rust; the metal knob is designed with anti-slip knurling, which is durable and can be used for a long time. Time Saving: Core drilling tool, easy to insert into the inner valve, control the core, no need to stop or release the refrigerant, easy to remove and install the valve core, save hours of emptying and charging time. Basic Operation of Valve Core Remover Wrench: 1. Remove the dead center on the valve stem, close the valve on the tool, adjust the connection between the tool and the air conditioner interface, and tighten the valve on the air conditioner.2. Make sure the tool is well connected to the air conditioner valve, then open the valve on the tool. Push the valve