Bicycle Disc Brake Modification Bracket Frame Adapter Disc Brake Holder Mountain Bike Converter V Brake Rack Cycling Accessories Specifications: Model: DS3001 70g Product Name: Mountain Bike/Road Bike Disc Brake Modification Bracket Used for: Used in the position where the bicycle has no disc brake installed, and used for refitting the disc brake. Description: The color of this product is black, the ring has three specifications, the inner diameter of the modified ring is about 22mm, about 31.8mm, and there are two options for small, medium and large. Description: Used for: Used in the position where the bicycle has no disc brake installed, and used for refitting the disc brake. Description: The color of this product is black, the ring has three specifications, the inner diameter of the modified ring is about 22mm, about 31.8mm, and there are two options for small, medium and large. Package Included: 1*Disc Brake Bracket