Fluoroelastomers are synthetic polymers that belong to the M class of rubbers, specifically to the rubbers where the polymethylene chain is saturated. The most well-known type of these rubbers is the fluorocarbon rubber FKM under the commercial name Viton. They can be composed of four different monomers: vinylidene fluoride (VF2), hexafluoropropylene (HFP), tetrafluoroethylene (TFE), and perfluoromethylvinylether (PMVE). There are various types of FKM depending on the fluorine content: with the higher fluorine content in the rubber, the resistance to chemicals is better. The process used to produce fluoroelastomers is radical polymerization in emulsion, and the standard methods used during shaping are pressing, injection molding, extrusion and calendering. Fluoroelastomers are extremely stable at high temperatures, resistant to flame, aging, ozone and oxidizing agents. They possess excellent mechanical properties, which, along with their other remarkable characteristics, contribute to the wide application of these materials. They are used in the automotive, aerospace, chemical, food and pharmaceutical industry as well as in the oil and gas industries. Their main use is in the production of seals, which can be O-rings, V-rings, flat or cut and rotary or piston seals. They are also used for pipes through which hot water and hot air passes, in cable insulation and for the other insulation purposes. The main manufacturer of the products made from fluoroelastomers is DuPont.