Snap-in wiper with a slotted heel. The slotted heel allows excess hydraulic fluid to bypass the wiper, preventing wiper blowout.
The outside diameter of the ring has a crush lip providing extra interference in the groove. A bead on the shoulder stops contaminates from entering through the groove. The inside diameter is ribbed to prevent pressure traps between the wiper and rod seal.
ST-XL (Hallite 520) wipers are direct replacements for ST or D wipers.