PIM bearing kit includes the inner and outer bearings and other parts. There is an proper order for the parts during the replacement process. Inner parts order from inside: Steel washer Washer Needle bearing Plastic washer Washer There is a black block in between these sets. Outer parts order from inside: Washer Needle bearing Plastic washer Two washers Key (not included) This is a spare part and no need to buy along with the machine.