This part is provided by the original manufacturer for Milwaukee power tools. The metal bearing is used to prevent friction between moving parts, and usually goes inside a gear. The item includes one needle bearing, and please be aware any associated parts are sold separately. Please refer to your models parts diagram for any additional parts.
It is a genuine OEM sourced item that is designed for use with Milwaukee power tools. This special bearing allows spindle shaft to rotate freely with minimal friction, over time the rollers of the bearing may begin to wear out and fail eventually requiring replacement. It is a high-quality component which is made of durable steel and it is sold individually.