High Quality MaterialsPU Leather Surface + Made by Sponge. On rainy days, you don't have to worry about the cushion being flooded. Just wipe the surface with a tissue and you can continue to use it. The thick sponge cushion is very soft and comfortable. The widening and thickening of the bicycle seat and backrest ensure a comfortable riding position. Easy to InstallA sturdy flat bike rack is needed to mount underneath. This bicycle rear seat easily fits on any bike rack, can be used on standard and univeral rear seats for most bicycles. Widely Used- This bicycle rear seat bike is easy to install on the rear bike rack, universal for most bikes, such as hybrid bike, touring bike, mountain bike, motorized bike, road bike, etc. Precautions: For your safety, please make sure you have tightened the screws well and double checked them before riding.