Walmart offers the Slime 4-Way Valve Tool with 4 Valve Cores for $1.87. Opt for in-store pickup to dodge the $5.99 shipping fee. That's $5 off list and the lowest price we could find. Buy Now Tips Amazon has it for the same with free Prime shipping. Features Remove valve core, re-tap threads and ream inside of valve Works on AC unit valves 4 replacement valve cores included Model: 20088