Padded shoulder straps and a breathable back panel reduce fatigue and keep airflow moving on long hauls. lightweight hiking backpack water backpack for biking skiing backpack mens hiking backpack About this item Perfect Size: The hydration backpack measures 10 inches x 5.5 inches x 18 inches (26 cm x 14 cm x 45 cm) 25 ounces (about 708 grams)and is suitable for teenagers, men, and women as a small hiking backpack. Whether you're hiking, cycling, running, or participating in any outdoor activity, this hydration backpack is the ultimate companion for keeping you hydrated on the go Water bag storage system: The biking backpack capacity is 15L, and the main compartment is designed with an independent waterproof and insulated water bag compartment, equipped with 2L water bags. The equipped 2.0-liter water bag is made of food grade PEVA material that does not contain BPA. The system uses an ergonomic high flow bite valve to ensure smooth movement and sufficient hydration during travel. Waterproof Protection - This hiking backpack with a water bag is made of durable waterproof nylon fabric, which keeps valuable items dry in light rain or splashes of water, ensuring peace of mind in unpredictable weather. The front cabin is equipped with a hidden mesh pocket for storing helmets and sports equipment. Comfortable and breathable: This water bag is designed with your comfort in mind, featuring padded shoulder straps and a breathable back panel to reduce sweating and stress. There are two zippered waist bags at the waist that can hold mobile phones and provide food supplies. Lightweight design ensures a balanced and easy to carry experience, replenishing energy even during long journeys Safety design: The shoulder strap of the cycling backpack is designed with a survival whistle and