ANV is a single acting double oil wiper. From the inside it works as a seal, providing additional protection against leakage of working fluid and residual oil film on the outgoing rod, and from the outside it acts as a wiper, preventing contamination from entering the cylinder. The special design provides the unique function of the umbrella that wraps around the front of the cylinder, creating an impenetrable barrier. This works especially well in vertically mounted cylinders where contaminants or fluid splashes build up on the cylinder.