Features: 15L cycling backpack, made of ultralight waterresistant nylon fabric. Special hole design for water bag (NOT included). 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.