4-valve manifolds with gauges,piston valve at two ends and diapgagm valve in the middle Description: Gauge Type:1.Pressure& temperature unit: PSI ... /Kpa ,oF/oC; Refrig scales& gauge diameter: R134a, R-22, R ... , R-404a, 80mm/3.5"3. Pressure& temperature unit:PSI/Kpa ,oF/oC; Refrig scales& gauge diameter: R12, R-22, R502, 80mm ...