... valve at two ends and diapgagm valve in the middle Description: Gauge Type:1.Pressure& temperature unit: PSI/Kpa ,oF/oC; Refrig scales ... -22, R-404a, R-407c, 80mm/3.5"2. Pressure& temperature unit: PSI/Kpa ,oF/oC; Refrig scales& gauge diameter: R ... -410a, R-22, R-404a, 80mm/3.5"3. Pressure& temperature unit:PSI/Kpa ,oF/oC; Refrig scales& gauge diameter: R12 ...