Features1Scope of Application: This metal gear replacement is used for center mid motor for TSDZ2 electric bike, gear replacing for mid drive motor. 2Metal Steel Material: Made of high quality metal steel material, which is durable and practical, and it can be used for a long time. 3Simple to Use: If you want to repalace the motor accessories, just directly installa and then finish the replacement, it is very simple, no effort and time. 4Widely Used: The mid drive motor upgrade part can not only used for the motor, but also can be used for the bearing of the central mid mounted motor of the electric bike. 5Lightweight: The mid drive motor upgrade part only weights about 163g / 5.75oz, so it is very easy for you to use when you need to repalace the equipment.SpecificationItem Type: Mid Drive Motor GearMaterial: Metal SteelGross Weight: Approx. 163g / 5.75ozProduct Size: Outer diameter: Approx. 37mm / 1.46inInner Diameters: Approx.12mm / 0.47in, 9mm / 0.35inHeight: Approx. 24mm / 0.94inPackage List1 x MidDriveMotorGear