15L cycling backpack, made of ultralight waterproof nylon fabric. , Special hole design for water bag (NOT included). , Rucksack Backpacks , Adjustable shoulder strap, chest strap and waist strap to fit your need. With whistle design on the chest strap. , Ergonomic design on the back for maximum breathability and comfort. Reflective strips for safe riding at night. , Rain cover included and mesh cover to put your helmet. Suitable for outdoor activities like cycling, rock-climbing and hiking, etc.