SUNPASS PTFE Braided Seal AP00001 is manufactured from an inert reinforced special fiber yarn, impregnated with PTFE and an inert resin to provide a non-stick surface. Other fiber material is available. SUNPASS PTFE Braided Seal With Silicon Core is designed for use on tank that handle aggressive cargoes under an inert gas blanket. It's elasticity is improved by silicon core.