Safety---- The hose can be connected quickly without refrigerant leakage. You don't need to pour any refrigerant into the air conditioner. It's 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 provides great convenience for connecting manifold hoses to the AC R134a car/auto system during diagnostic, charging, or evacuation work. This brand new set of 2 color couplers provides you with the great convenience of attaching the manifold hoses to the AC R134a auto/car system during diagnosis, charging, or venting. It can quickly connect the hose without refrigerant leakage, and you don't need to pour the new refrigerant into the air conditioner, which is very safe and convenient. Features: 1. 1/4 male flared fitting for automotive air conditioning service. 2. Red for the high side...