PYREX / CORNING
NIB CORNING PYREX 3/4" X 9-3/8" SIGHT GLASS 500F 90 PSI ANNULAR EDGE (DD4)
With Oxford cloth, you get a material that ages well and looks better over time.
PYREX 3/4" X 4" SIGHT GLASS 500 Degrees Fahrenheit 450 PSI High Pressure
I grabbed the PR1G.75X50X5 Resin Fiberglass kit for a quick patch on a trailer fender.