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 degreesF. COMPATIBLE WITH US GAUGE P-590K AND P-600 AND ASHCROFT 1495A. CLEANED TO ASME B40.100 LEVEL IV. UL APPROVED. WARNING: This product can expose you to chemicals including lead which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65warnings.ca.gov - Lead