About this item [LIGHTING YOUR JOURNEY!]: Weighting 0.78 lb, the hydration backpack is a lightweight, reliable, and comfortable water backpack. Made of ultralight and durable fabrics, the water backpack makes you feel more comfortable while running, hiking, and cycling. Breathable & airflow system to keep your back cool and dry. Soft cushions on the rear of the backpack to comfort your back. [PROFESSIONAL & CONCISE DESIGN]: The design of the hydration pack is very simple and concise, cutting down extra layers and weight. Comes with adjustable shoulder, chest, and waist straps, and the hydration fits perfectly between most shoulder blades. The reflective straps and whistle buckets can ensure safety at night. It's bounce-free while running and cycling fit men, women, and kids. [FRONT POCKETS & INSULATED LAYER]: Comes with a front pocket, the hydration daypack can put small items easily, such as a phone, and snacks. The water bladder compartment contains an insulating layer, which can keep your liquids cool for up to 4-6 hours. It is perfect that you can enjoy the fresh cool water while doing outdoor activities. [2L TASTE-FREE HYDRATION BLADDER]: hydration bag with a 2L BPA-free water bladder that is made of food-grade class EVA material. A large opening design is easy to add ice and cleaning to the bottle. The black insulated sleeve can keep the water cool and prevent scratches.