The function of the Aston Seals SAP wiper ring is to prevent introduction of dust, dirt, foreign matter and heavily deposited ice and mud into the system. This is achieved by a special wiper lip which produces a very effective cleaning action, prevents the development of scores, protects the guiding parts and extends the service life of the axial moving rod seals. An external sealing lip on the outside diameter contacts the housing in order to prevent moisture entering the groove. The internal ribs give stability, back pumping ability and prevent sticking of the wiper in the groove. The material used to produce this wiper is a special polyester resin that ensures excellent properties in case of heavy applications, an increased wear-resistance and an extended service life.