The G642 Series back mount closed circuit sight gauges provide 270° of viewing the fluid level clearly delineated by a redline on white background integral to the sight glass all secured within an aluminum body (HIGH-LOW markings). A wetted front facing dial thermometer provides an analog display of the fluid temperature. Standard Features: 5 inch centerline length Back mount .90 inch SQ body machined from extruded aluminum bar stock 270° of viewing the fluid level (.50 inches wide) Viewing enhanced by redline on white background integral to sight glass 2.00 inch diameter dual scale dial thermometer, 0° to 300°F and -20° to 150°C Aluminum tube shields thermometer probe extending into reservoir HIGH-LOW markings on aluminum body 1/2-20UNF mounting studs accommodate reservoir wall thicknesses up to .75 inches Suitable for use with most hydraulic and machine lubricating oils Pressure Rating: 125 psi (862 kPa) maximum operating pressure at 150°F (65°C) Access to inside of reservoir is required to mount this style sight gauge. Caution: Not recommended for use with steam, acidic fluids, caustic fluids and volatile fluids. If aluminum construction is selected for a water application, anodizing is recommended. Reservoir must be drained to remove dial thermometer or loss of fluid will occur