Roller Rack converts almost any 20 (406) or 22 inch (451) wheel size foldable bikes and foldable e bike into an instant fold & roll. Rack and Trolley 2 in 1. (Rack only ). Made of laluminium. Forget about heavy carrying and frustration in getting the folding bikes around. With Easy Roller Rack you can move your bike around easily. Great for people who commutes in Buses and train.