This set of 2 color couplers offer you the great convenience to attach the manifold hoses onto the auto/car R134a system during the diagnosis, charging or evacuation working. It can quickly connect the hose without leaking refrigerant, and you don't have to pour the new refrigerant into the air conditioner, which is very safe and convenient. Features: 1. Red for high pressure side and blue for low pressure side. 2. High & low couplers kit with colored knobs for easy identification. 3. Reliable and safe for valve access to systems even at working pressure. 4. Made of copper material, solid, durable and corrosion proof.  5. Exquisite workmanship, stable performance and high reliability. Specification: Item Type: Quick Coupler Material: Copper Color: Red + Blue High Side Coupler: Red Low Side Coupler: Blue  Applicable: Universal   Package List: 2 x Quick Coupler