Vacuum-grade best FFKM O-rings seals achieve 10⁻⁹ Torr ultimate pressure with outgassing rates below detectable limits. Perfect for load locks, beamlines, and space simulation chambers. No virtual leaks even after 300°C bake-out. Aerospace and research labs specify the best FFKM O-rings seals for UHV performance. https://globalsealstech.com/ffkm-seals/