Arctic Freeze Reusable R-134a Gauge & Hose features a diagnostic gauge, easy-to-use trigger dispenser, and ninety degree coupler. The gauge is able to diagnose if a recharge is needed, identify the current low-side pressure in the system, and determine increases in pressure during the recharge process. This product is designed for EPA compliance and to work only with R-134a cans with self-sealing valve can tops.