STd  rubber sliding Sstep seal is a two-piece design consisting of a filled PTFE cap that is powered by a standard size O-ring. The wiper and seal design of the GSI assist the main rod seal against leakage by helping to seal the fluid in the cylinder as it extends. The outer sealing edge prevents contaminants from entering the system when the piston rod is retracted. Wiper seal is a double-acting wiper for low to medium hydraulic cylinders. The function of the wiper ring is to prevent dust, dirt, sand and metal chips from entering the axially moving rod and piston.As a result, the occurrence of scratches is largely prevented, the guiding elements are protected and the service life of the seals is extended.