Safety----The hose can be connected quickly without refrigerant leakage. You do not need to pour new refrigerant into the air conditioner. It is very safe and convenient. Even under working pressure, the valve can enter the system safely and reliably. Easy to use ---- This new two-color coupler offers great convenience to connect the pipes from the manifold to the car system /auto AC R134a during diagnostic, charging or evacuation work. Description: This brand new set of 2 color couplers offers you the great convenience of attaching the manifold hoses on the auto/car AC R134a system during diagnosis, charging or evacuation. It can quickly connect the pipe without refrigerant leakage, and you dont have to pour the new refrigerant into the air conditioner, which is very safe and convenient. Features: 1. 1/4 male flare fitting for automotive air conditioning service. 2. Red for the high pressure side and blue for the low pressure side. 3. High Low coupler kit with colored knobs for easy identification. Specifications: Material: Solid Brass Metal Color: red + blue High side coupler: red Low side coupler: blue Connector: 1/4 male flare fitting Quick joint: air conditioning Suitable for: R134a valve core