The G605 Series front mount closed circuit sight gauges provide front viewing of the fluid level clearly delineated by a redline on white background integral to the glass sight all secured within an aluminum body. HIGH-LOW markings are stamped into the aluminum body. Standard Features: Centerline lengths from 3 to 12 inches Front mount .90 SQ body machined from extruded aluminum bar stock Fluid level visible from front of gauge (.50 inches wide) Viewing enhanced by redline on white background integral to sight glass HIGH-LOW markings on aluminum body 1/2-20UNF mounting studs accommodate reservoir wall thicknesses up to .62 inches Suitable for use with most hydraulic and machine lubricating oils 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.