Schwinn Bike Deluxe Rear Rack, Lightweight, Can Hold Up to 20 lbs. Loads, Durable Steel Rails, Designed with Extra Tie-Down Points, Fits Most Adult Bikes, Black - Rear rack mounts easily to seat post, lightweight compact design, alloy construction carries up to 20 lbs. - Side rails are ideal for mounting pannier bags; come with extra tie down points for securing the load - Comes with 3 Seat post shims to mount the seat post to the seat tube of the bicycle - Seat post must be removed from the bike to install; use the included plastic shims to create a tight fit between the rack and the seat post - Fits perfectly on a post 1.25 inches, must use shims for smaller diameter posts, attaches to the seat post only