Digital gauge with guided command Guided Commands eliminate the guesswork 24” Long Hose Trigger Dispenser Quick Connect Coupler The A/C Pro R-134a Professional Digital Gauge & Hose provides guided commands which help eliminate the guesswork when recharging a vehicle A/C system. It features an easy-to-use trigger dispenser, 24″ hose, and a quick-connect 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 compatible with both sealed and self-sealing R-134a cans.