PAS SENSOR: Speed sensor. Reduction Ratio: 1:21.9. 1 Display (Optional, if you choose no display, the parcel will not include). 1 Screw and Nut Accessories Set. 1 Bottom Bracket Remover. Note: The motor is designed to fit bottom brackets with a width of. And an inner diameter of. Please note that the motor kit does not include screws for 73mm bottom bracket.