SHIBATA (DR-HPM) Replacement sensor unit for SHIBATA DR High Performance Motors. If abnormal noise or wear reoccurs even after replacing the rotor with a new one, it is likely due to wear caused by seizure of the sensor bearing or problems with the circuit board due to heat, so we recommend replacing this as well. The included bearing cover is for clearance adjustment. Please use it according to your needs. Comes with a transparent bearing cover. I have several spares, and some packs have been used. Operation confirmed.