Flexzion Adjustable Bike Cargo Rack, Universal Extendable Aluminum Seat Post Rear Carrier Bicycle Touring Mount for Heavy Luggage Saddle Equipment Gear, Black Rust Resistant Aluminum Alloy Construction allows up to 20lb weight capacity. Easy to Install: Quick release mechanism makes installation a breeze Fits seat posts between 10 to 12.5 inch. Ideal for road bikes, mountain bikes, fat bikes, touring bikes Adjustable, extendable rear rack makes it easier to load cargoes. Includes rear reflector to keep you safe during night outs Side frame is ideal for attaching saddlebags, luggage, and other accessories