"MASS", Weatherproof gauges are commonly used in Chemical Processing, Petroleum Refinery, Petrochemical, Fertilizer, Thermal & Nuclear Power generating industry & process applications. Mounting Direct with bottom EntryDirect with back entryFlush Panel with back entry(Three hole panel or bracket type)Surface with bottom entry,Joints S.S. Bourdon tube tip and the socket ends are ARGON ARC WELDED and phosphor bronze bourdon tubes are silver brazedsoldered. Bourdon tubes are heat-treated and stress relieved,Extra Fitments Micro Zero Adjustment Pointer Neoprene blow out disc.