3M™ Dyneon™ Fluoroelastomer FE 5621 is a copolymer of vinylidene fluoride and hexafluoropropylene with a fluorine content of 65.9%. This fluoroelastomer (FKM) is the low-shrinkage version of 3M™ Dyneon™ Fluoroelastomer FE 5620Q, and can be used in transfer and injection molding, extrusion and calendering. It offers improved scorch resistance at high molding temperatures.