AN Wipers

AN-Style Snap-In Wiper Seals

AN wiper seals are an axial seal that creates a seal while allowing a reciprocating shaft to pass through the seal's inner bore. AN style excluders are designed to ensure proper fit with all MS-28776 (MS-33675) dash size grooves. The slotted heel design prevents pressure traps from forming between the rod seal and wiper. This profile of wiper requires very little radial or axial space. This is why they are ideal in light to medium duty hydraulic and pneumatic applications where such space constraints are present.  Wiper seals are often used for fluid containment and to prevent dirt from entering a reciprocating shaft mechanism.

Link: AN Wiper Seal Groove Dimensions