Waterproof Material: Bike pannier rack is made of PU leather and waterproof fabric to keep things dry. The fabric is also tear and scratch resistant. Your items can be protected from wind and rain. It can be used on all bikes with rear seats. Night safety: Reflective tape increases visibility at night. Due to the large area of \u200b\u200bthe reflected light and the black fabric that reflects the light, the appearance will not be affected during the day. Reflective elements ensure better visibility and safer riding at night. Large Capacity: The bike seat bag has a main compartment, two side pockets and two back pockets with a capacity of 8 liters, which can store bike repair tools, water cups, power banks and clothes can be kept. The reflector holder on the back of the car bag provides space for the taillights and ensures more visibility and safety. 3-in-1 multi-function pan frame: Trunk bag bicycle has a movable and adjustable shoulder strap, which is very is comfortable to wear and reduces strain on the back. It can be used not only as a bicycle pannier, but also as a shopping bag and shoulder bag with adjustable shoulder strap. Easy Installation: Fastening straps can be easily and quickly installed on all bikes with rear seats and tool-free installation, such as mountain bikes or racing cars. This lightweight and easy-to-carry backpack is perfect for outdoor activities such as travel, hiking and mountaineering.