The BOX One Disc Brake Adaptor comes in two configurations, one that is compatible with frames with "sliding dropouts" and one that's compatible with "standard dropouts". Both are manufactured to suit 140mm rotors. Read carefully through the fitment guide on the Specification tab to ensure you select the correct adapter for the frame type you are fitting this adapter to. The all NEW Box Disc Brake Adapter is designed to help improve braking control on frames where disc brakes were not standard. Compatible with 2 types of dropouts and 3-10mm hubs, in the right configurations, the Box Disc Brake Adapter goes over your hub’s axle and mates with the frame’s dropout, allowing mounting of a standard post mount disc brake caliper. The Box Disc Brake Adapter is NOT compatible with all frames, and purchase/installation requires special attention to your frame’s dropouts for compatibility. We do not recommend composite frames for this adapter. There are two different versions of the Box Disc Brake Adapter. Standard 10mm Dropouts - Standard dropout configuration, dropout must be between 6-8mm thick, and have a flat inside face. Found on many frames as this is a common standard, Sliding Plate Dropout - Found on many Thrill, Haro, DK and Stay Strong aluminum frames The Box Disc Brake Adapter has many related components available from Box Components. Box Three Pro Disc Hub. Box Three Brake Caliper. Box Three 140mm Disc Brake Rotor. ALL Box Brake Levers. Box Linear Brake Cables. Box Disc Brake Adapter Installation Instructions Assess your hub and frame configuration. (See instructions above) Select the proper components for your hub and frame. Install the brake rotor onto the hub. Install the adapter ring onto the hub. (If applicable) Install the Brake Adapter onto the adapter ring, or hubs axle for Box Three Hubs. Install the hub with brake adapter on to the frame. Ensure the adapter tabs are completely inside of the dropouts : you must run the chain length that allows for best full engagement of the adapter on dropout. This may require a half link. Note: some configurations may require the dropouts spread for pro proper adapter fitment. This version is compatible with specific sliding plate dropouts with inserts. Please see the compatibility section for more details.