Monitoring the status of rotating components accurately is essential for many applications. This is particularly true for AC motors that require encoders to measure the speed and the direction of rotation continuously. SKF® Motor Encoder Unit, Cylindrical Bore, Series: BMB Series, 20 mA, 20 mm Shaft Dia, 10000 RPM Limiting Speed Rating, 0.25 W Supply, Shaft Mount, Sealed Enclosure, -40 to 255 °F Operating, Steel, Uncoated, 47 mm OD x 14 mm W Dimensions