Robinair (18190A) R-134a Low Side Service Coupler with Blue Actuator Chrome plated brass, low-side manual coupler with blue actuator Connects to Robinair Enviro-Guard hoses to allow access to service ports on automotive R-134a A/C systems Quick-connect design has an integral safety sleeve that protects against injury and refrigerant loss if the coupler is disconnected under pressure Compact design easily fits into tight quarters - especially handy for retrofits The 6-ball coupler design provides a more stable grip on the fitting than lesser 4-ball designs