Specifications

FFKM Seal O-Ring
FFKM parts last longer and seal more effectively than other elastomers in demanding processing environments.
Perfluoroelastomer (FFKM/FFPM) parts resist over 1,800 different chemicals, while offering the high temperature
stability of PTFE (327°C).
They're used in highly aggressive chemical processing, semiconductor wafer fabrication, pharmaceutical, oil and gas recovery, and aerospace applications. The long-term, proven performance of FFKM parts can mean less frequent seal changes, repairs and inspections, increasing process and equipment uptime for greater productivity and yield.
FFKM parts and seals also help prevent semiconductor process contamination by reducing particulates, lowering extractables, and resisting degradation in harsh plasma. FFKM parts provide low outgassing in vacuum-sealing applications. Food grade-compliant seals are also available for food, beverage or pharmaceutical processes.

We also have AFLAS PM-3000 Chemical Resistant FFKM O RING
It with better price than Kalrez