The GA613 Series front mount closed circuit sight gauge is mounted securely with end blocks made from aluminum. These end blocks are connected with a clear, rigid tubular nylon sight providing 360° viewing of the fluid level. The nylon sight combines rigidity with break resistant toughness. Pipe adapters are provided with the gauge for mounting directly to NPT couplings. Standard Features: Centerline lengths from 3 to 12 inches Front mount .88 inch square end blocks machined from aluminum bar stock .81 inch diameter tubular sight 360° of viewing fluid level 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 Temperature & Pressure Ratings: 225°F (107°C) maximum operating temperature 125 psi (862 kPa) maximum working pressure at 70°F (21°C) Caution: Not recommended for use with diesel fuel, gasoline, ethylene glycol (antifreeze), polyglycols, ethyl alcohol, methyl alcohol, methyl ethyl ketone(MEK), acetone, isopropanol, water exceeding 194°F (90°C), steam, acidic, caustic and volatile fluids