Faswin Retractable Bike Mount Cycle Bicycle Rear Seat Post Rack Compatible with most bikes.Adjustable length Ideally used with panniers, backpacks, baskets, etc. Made of high quality hard Aluminum Alloy,durable and sturdy Easy to install,quick-release bag mounting system Dimension:approx 34cm x 12 cm(L X W).Supports up to 22lb of cargo