Fiber-reinforced oil seals contain no metal parts with the exception of the spring. Instead of the metal insert, a reinforced-fiber component is molded into the body of the seal. Damage through transport and mounting is consequently excluded. Fiber-reinforced oil seals are mainly used for installation in equipment with large diameters. The use of an axial retaining plate is necessary, except for the type TRJ/F and respectively for the type TRL/F.