Midwest Control SGHP-100RF Sight Glass with Built in Reflector, 1" MPT, Nickel Plated Steel, 1250 psi, 1.38" x 1.06": Amazon.com: Industrial & Scientific
Size 8 Type A, High Pressure 12-5/8" Gauge Glass | APG
5" x 5/8" OD High Pressure Borosilicate Tubing Sight Gauge Glass w/ 2 Gaskets | eBay
USA Lab High Pressure Triclamp Sight Glass 1.5", 2", 3" - 350PSI - USA Lab