Meet the complete set for valve core care. Use the Slime 4-in-1 valve tool to remove the valve core re-tap threads and ream the inside of the valve (also works on A.C. unit valves). Includes 4 replacement valve cores. The Slime Four-Way Valve Tool is designed to be used to remove the valve core re-tap threads and ream the inside of the valve. This tool works on AC unit valves. Four replacement valve cores are included for your convenience so you can have them on hand when needed. The four-way tire valve tool has a compact size that is simple to store in your workshop until you have to use it. With a durable construction they are made to last for a long time to come. It is simple to work with.