It is a genuine manufacturer-sourced replacement o-ring which is specially designed for use with Chicago Pneumatic impact wrenches. This o-ring provides an air-tight seal between connected pieces, over time the material may wear out and begin to crack eventually requiring a replacement. Keep in mind this high-quality component is made of durable rubber and is sold individually.
This is an authentic Chicago Pneumatic replacement part that has been sourced from the original manufacturer to be used with impact wrenches. The ball bearing is used to reduce friction between a rotating shaft and a fixed part assembly. This bearing is sold as an individual replacement part.