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.
Snap-in rod wiper molded from 90A durometer urethane.
AN wipers are ideal for light duty and pneumatic applications. Its main purpose is to prevent dirt and contaminants from entering the hydraulic or pneumatic systems.
AN wipers will retrofit into glands prescribed in MS-33675 for corresponding dash numbers of MS-28776.