Flow Sight with Nylon Ball, Inline Double Window, 1/4 In.-18 NPT, Hex Dia. Flats (In.) 7/8 in, Max. Working Pressure (PSI) 435 psi, Max. Operating Temp. 180 Degrees F, Sight Length (In.) 1 1/16 in, Sight Dia. (In.) -, Overall Length 3 9/16 in, Aid in Viewing of Dark Fluids in Dim Light Conditions, Condition or Clarity, Vertical or Horizontal Fluid Lines to Observe Fluid Flow, Features Buna N Seals and Borosilicate Sight Window, Female x Female NPT, Solid Brass Bar Stock Construction