https://www.mcmaster.com/#1079k14/=19teha2
$13.38
McMaster Part No: 1079K14
High-Pressure Sight for Clear Liquid, Nickel-Plated Steel, 1 NPT Male
Window Diameter: 1"
Maximum Pressure: 1,250 psi @ 70° F
Temperature Range: -40°F to 500°F
For Use With: Water, Hydraulic Fluid, Diesel Fuel
Material: Steel
Finish: Nickel Plated
Window Material: Glass
Features: Fused Window
For Liquid Type: Clear
With a thick glass window fused to a metal body, these sights resist cracking at high pressures.
-CB