Features: 18L cycling backpack, made of ultralight water-resistant and tear-resistant nylon fabric. Special hole design for water bag (NOT included). Adjustable shoulder strap, chest strap and waist strap to fit your need. Mesh and poriferous EVA design on the back for maximum breathability and comfort. Reflective strips for safe riding at night. Mesh cover to hold your helmet. Rain cover to be used in heavy rain. Detachable pouch for store your cellphone. Suitable for outdoor activities like cycling, camping, mountaineering and hiking, etc.