Product Description Size: 43*18*23cm Color: sky blue, rose red, black Material: Oxford cloth EVA, PVC Package content: 1 pc outdoor backpack 1 pc outdoor sports water bag 1. LIGHTWEIGHT & COMFORTABLE: With the adjustable shoulder/chest/waist straps, the hydration backpack adapts to all body sizes and the ergonomic design and breathable material ensure high wearing comfort for men, women and youth. 2. RELIABLE: Thanks to premium nylon material, our cycling backpack is robust. The splash-proof material keeps your belongings dry and clean in light to moderate rain. Reflectors and integrated signal whistle ensure a high level of safety. Suitable for outdoor activities such as cycling, running, hiking, climbing etc. 3. WONDERFUL SPACE: The cycling backpack has been designed with a main compartment for a 2L hydration bladder, a small pocket for small items such as a smartphone, keys or two muesli bars and an elastic band for sun protection clothing and towels. 4. REPLACEABLE 2L BLADDER: The included 2L hydration bladder uses FDA-approved BPA-free material and has an enlarged screw cap that makes it easier to fill with liquids. Perfect for filling with ice cubes or various sports drinks. The bladder's internal airflow system is heat-insulating and provides you with cold water all the time on the go. 5. SAFETY IN MIND: Reflective safety tabs and reflective logo for high visibility in low light, keeps you safe and hydrated for most extreme environments and weather conditions, use food grade material for the bladder.