The G608 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). Brass pipe adapters with integral needle valves are provided with the sight gauges for direct assembly of the sight gauge to NPT couplings. The needle valves allow a user to shut off flow to the sight gauge allowing the sight gauge to be removed from the reservoir with minimal loss of fluid. Standard Features: Centerline lengths from 3 to 30 inches Front mount .90 inch 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 1/4, 3/8, 1/2 or 3/4 inch NPTF pipe adapters machined from brass bar stock Suitable for use with most hydraulic and machine lubricating oils Caution: Not recommended for use with water, steam, acidic fluids, caustic fluids and volatile fluids.