1.12 24L LARGE CAPACITY: with a maximum 24L storage capacity and two outer pannier bags. The bike trunk bag has enough space to store your cycling essentials. The elastic drawstring on the trunk bag helps secure extra items you need. 2.2 WATERPROOF RAIN COVERS: The rear bike bag also includes a black rain cover in the bottom and a green rain cover in the trunk bag, so you don't have to worry about cycling in the rain. The bike rear bag is made of reinforced polyester material, making it durable. 3.EASY INSTALLATION: The bike rear rack bag has several adjustable straps, allowing it to attach to a bike rear rack in seconds without any tools, making it suitable for most bike racks and mountain bikes, road bikes, e bikes. 4.REFLECTIVE STRIPS TAILLIGHT HOOK: The reflective strips on the bike trunk bag provide better visibility. The hanger on the back can hold a taillight, further increasing cycling in low light conditions.