Detailed Product Description Ammonia Gauge SpecificationsDial2.5"(50mm),4"(100mm),6"(160mm)CaseStainless steel / Black Paintied SteelLensPolycarbonateRingStainless steel / Black Paintied SteelInternalStainless steel / Painted steelConnection 1/4" NPTRange30-0-150 PSI/F, 30-0-300 PSI/FAccuracy±1.0%,±1.5%,±3-2-3%