Mechanical Manifold Gauge Set, Number of Valves 2, R-12, R-22, R-502, Number of Hoses 3, 36 in, 0 to 500 psi, 30 in Hg to 350 psi, 1/4 in, Brass, Full Flow Dual O-Ring Valve Design for Fast, Trouble Free Performance, Precision Flutter and Pulsation with Protective Gauge Boots, UL Recognized Barrier Hose