V201 a Fluorosilicone rubber combines the good high and low temperature stability of Silicone with the fuel oil and solvent resistance of Fluorocarbons. It is most often used in aerospace applications for systems requiring fuel and/or diester-based lubricant resistance up to a dry heat limit of 400° F. V201 features good compression set and resilience properties. Suitable for exposure to air, ozone, chlorinated and aromatic hydrocarbons.

Due to limited physical strength, poor abrasion resistance and high friction characteristics, Fluorosilicone is not recommended for dynamic sealing applications. They are designed for static sealing use. Also they are not recommended for exposure to brake fluides, hydrazine, or ketones.
Temperature Range: -100°F to 347°F (-74°C to 175°C)

F201 Kalrez® (Trade name of DuPont) is made from a Perfluoroelastomer possessing exceptional resistance to degradation by aggressive fluids and gases. Kalrez® combines the high temperature resistance of Fluorocarbon Elastomer (such as Viton®), with the chemical inertness of Teflon®. Kalrez® provides long term service in virtually all chemical and petrochemical process streams. Kalrez® parts are offered in several compounds with varying tensile, elongation, hardness, compression set and temperature range. Kalrez® is used for sever chemical exposure and high temperatures. Used in oil exploration and refining for chemical processing and transportation.

Because of its high cost Kalrez® is generally used when no other elastomer is appropriate.

Kalrez® should not be exposed to molten or gaseous alkali metals (sodium). It also can significantly swell upon exposure to some fluorinated solvents, fully halogenated freons, and uranium hexafluoride.
Temperature Range: -58°F to 302°F (-50°C to 150°C)