CASE SIZE: 1.5",2",2.5",3",and 4" CASE MATERIAL: Black abs case and plastic case TUBE&SOCKET: Brass,stainless steel,steel with nickel plated,316stainless steel,phosphor bronze and so on. MOVEMENT: brass,stainless steel Connection: 1/8", 1/4", 1/2,3/8 BSP,NPT or BSPT dependent on model &size. bottom, back, left side connection, lower back connection. '''''''' AVAILABLE RANGES: Vacuum&compound through 500psi, 600psi, 5000psi, lO,OOOpsi and so on. WINDOW (LENS) MATERIAL: Snap on plastic window, snap in plastic window, screw in polycarbonate window,plastic welded window. ACCURACY: ASME B40.1 Grade B (3-23-3%)