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 Resistant with Protective Gauge Boots UL Recognized Barrier Hose