P.T.F.E. Polytetrafluorethylen Rubber O-rings

P.T.F.E. is an extremely inert material and is unaffected by virtually every known chemical including almost all acids, alkalis and solvents.
These exceptional properties make P.T.F.E. an ideal material for O-ring Back up Rings. It's cold flow characteristics under permanent strain are usually a disadvantage in P.T.F.E. O-Rings, e.g. It has little memory to return to its original form.
Tempurature Range -195°C to +250°C