Due to the difference in color between the photo and the display and screen, there is a slight color difference, which is normal. Suitable for Bafang mid-mounted BBS 01 02 / BBSHD mid-mounted motor chainring replacement Number of teeth: 42 teeth (positive tooth thickness 3.6mm*21/negative tooth thickness 1.9mm*21) Maximum diameter: 175mm Maximum height: 14mm/HD version height 24.3mm Offset (from the mounting contact surface to the outer side of the tooth) BBS 01 02 version is about 10mm/BBSHD version is about 20.5mm Tooth pitch: supports 6-7-8-9-10-11 speed chains Threaded hole diameter: 5.2mm Inner hole diameter: 41.2mm Exterior color: black Surface treatment: sandblasting + anodizing Surface roughness: about 120 mesh Net weight: BBS01-02~155g/BBSHD~177g Packing size: 24*24*5CM BBS 01 02 series dedicated: BBS HD 1000W Bafang mid-drive motor adapts to: Before installation: Effect display after installation :