This compressed gas gauge features a Bourdon tube with low copper content for pressure ranges 800 PSI and below, making it safe for use with acetylene. Lower mount connection. Wetted parts are made from a brass copper alloy. Polished brass case provides long-lasting durability. Removable twist-off polycarbonate window. White aluminum dial. Ambient operating temperature range is -40 to 140°F. Compatible with US Gauge P-590K and P-600, and Ashcroft 1495A. Cleaned to ASME B40.100 Level IV. UL approved.