1.No disc brake fixed seat frame Disc brake conversion seat road car Small fold Small diameter modification Oil disc Wire disc No need to change the frame 2.No disc brakes, the gospel of the riders! ! A2Z Discless Brake Frame The adapter does not need to change the frame to change the disc brakes. It is OK to install this 3.Road bikes, mountain bikes, small folds.90% is no problem! 4.This device will not be displaced due to the removal of the rear wheel. 5.How can I tell if your car is usable? 1. The rear Triple-cornered shape is a normal Triple-cornered . Not too strange shape.2. The wheel set must be a quick release wheel set. No Disc Brake Fixed Seat Road Bike Bicycle Disc Brake Adapter Converter Tools used: 4mm / 5mm Hex key (not included) Weight: 125g with screws size:Applicable frame spacing: 70/45mm Material:metal colour:Black+silver Package Contents: 1 x Bike No Disc Brake Fixed Seat Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.