Palmetto Packing 981 Chekseal is a self-adjusting axial lip seal. It is an exclusion device designed to deflect and exclude contaminants, such as water, dirt, dust and mud. It also prevents the loss of viscous lubricants and heavy greases. This Chekseal features highly resilient rubber construction that can be stretched and adjusted to fit the surface of the shaft. It also serves the purpose of a retainer seal by preventing the loss of viscous lubricants. These shaft seals have resilient nitrile butadiene rubber (NBR) construction, offering natural tension to hold the seal in place while the shaft turns.