Swagelok® Vac Goop is a Fluorosilicone based thread lubricant - can be used with: threads, o-rings, gaskets, glass seals and metal parts in vacuum systems - resists galling, has extremely low vapor pressure, minimizes outgassing, compatible with a wide range of materials, with stands temperatures up to 300 Degrees Fahrenheit (148 Degrees Celcius), resists moisture (1 oz tube)