Durable Material - Well made by environmental material. Extendable and Retractable - Fold the mudguard when sunny, keep the cool appearance. Stretch the guard when raining, protect you from mud. With Allen Key - Using a small Allen key is easy to install or remove. Keep Your Bike Clean - Wide and elongated design can prevent your bike from mud and rainwater to keep dry and clean. These mountain bike fenders are easy to wash and reassemble. Note - Before installing the front mudguard, you need to check if there is a mounting hole in the front beam of the bike, then align the mudguard tile and the beam and tighten with screws.