The running holiday vest is designed with 2 storage compartments which can hold a 2L water bladder and a 500ml soft bottle respectively (the bladder and soft bottle are not included), you can drink directly by biting, so that you can keep hydrated at any time, anywhere, and it will not affect your rhythm at all. The elastic straps on the front of the backpack, combined with the hose straps, ensure that you won't wobble, bounce or make any noise when drinking. Amazing Design Unleash Your Inner Adventurer with THIS 5L hiking backpack. The main compartment is perfect for storing clothing and first aid essentials, the bottom zippered pocket is ideal for storing valuables (keeps up to a 5.5" cell phone) and the unzipped pockets are designed to store energy supplies and sunglasses for easy lit. Reflective logos and strips on the front and back increase safety in low visibility situations, making every run longer, safer and more comfortable. Adjustable DesignThe unisex running backpack features 2 adjustable sternum straps with adjustable shoulder straps for a comfortable and snug fit throughout your run. The adjustable feature is designed to minimize bounce and shifting and prevent chafing due to misalignment. Superior QualityMade of high quality ultralight Nylon, lightweight, low resistance, light and wear-resistant; the soft and breathable mesh on the back and the men's straps accelerate the flow of blood air and wicks away moisture, preventing discomfort caused by heat build-up, keeping your back cool and toasty in comfort. The wide mesh men's vests help take the load off your shoulders, perfect for outdoor sports. Whether you're road cycling, hiking, marathon running, trail running, or just enjoying a quiet time, this waterproof vest backpack is an excellent choice due to its unmatched transcapacity, thoughtful storage, and overall comfort. It's also suitable for cycling, hiking, running, skiing, horse riding, mountaineering, hunting, racing, and training, making it a great gift for your friends and family who love outdoor sports.