This is an authentic replacement part sourced directly from the manufacturer. The ball bearing is commonly found in Craftsman generators and power tools such as bench grinders and drill presses. This part is made of metal, and is generally used to allow components to spin freely. It may be found in various locations in the machine, dep...Read moreending on model. Please refer to the parts diagram to be sure of ordering the correct part. You may require a screwdriver or wrench when replacing this part. This is an individually sold item.