Orion Motor Tech Adjustable R134A Quick Coupler Connector Adapter with 1/4" SAE Fitting for High Low AC HVAC Manifold Gauge & Hose Set. Fits A/C manifold gauge sets (R-134A type), coupler interface fit with R134A service ports, 1/4" male flare. Adjustable coupler (6 ball style) is compatible with all models (competition: unadjustable couplers are NOT compatible with European models). Accurate snap lock and knurled grip ring for easy operation; detachable copper adapter for easy maintenance; both top and bottom knurl are colored for accurate maneuverability. Premium quality, aluminum construction for the low-side (Blue) & high-side (Red) switch; nickel plated bronze for the body; bronze construction for the ACME adapter Method of use: connect bottoms with vehicle's R134a service port; connect the ACME adapter with the refrigerant hose; turn on/off the switch at top to turn it on/off. New in Package