AFTER SALES SERVICE: Miracol teams offer a 100% satisfaction guarantee, and we are dedicated to providing the best customer services and shopping experience. If you have any problems or questions with our product, please feel free to contact us. The compact structure and small size of our packs make it a terrific companion for runners, and it is also a decent festival gift for friends and family. It's a great outdoor pack for men, women, kids, boys and girls, so buy now and start your journey!. CARRY ALL YOUR NECESSITIES: This small but compact water bag has a total of three layers, including an easy-to-use mesh front pocket and 2 other inner pockets, which will ensure that you have enough storage space for different accessories. The front pocket can hold your phone, wallet, keys, sunscreen, energy bar, etc. The waterproof insulation layer pocket is especailly designed for holding the 2L water pouch, and the other inner pocket can hold your clothes, towel, books, etc. MEET YOUR HYDRATION NEEDS: The lightweight insulated water backpacks comes with a 2 liter BPA-free water reservoir with a large 3.1" opening for easy filling and cleaning. The inside aluminum foil thermal insulation layer keeps your water cool for a minimum of 4 hours, perfect cooler gear for your day-long hydration needs. Its good heat insulation can also keep your lunchbox warm and food fresh. You can enjoy drinking cool water and eating fresh food whenever and wherever you go!. DESIGNED FOR YOUR COMFORT: Adjustable chest and waist straps can make the backpack fit your body perfectly, reducing shaking and friction while riding a bike on the trail or mountain. The mesh shoulder straps are highly breathable and allow your arms to move freely to control the rhythm of your run. Comfort features also include an air back panel that is filled with highly breathable mesh padding, allowing air to flow through your back to ensure the maximum comfort for you during travel. LIGHTENING YOUR JOURNEY: This hydration backpack is especially designed for biking and running. Weighing only 0.3kg, this pack is so light that you'll hardly know you're wearing it. The hassle-free water supply, excellent insulation layer and feather-light material of this water backpack will bring you a different wearing experience. It is also great for hiking, camping, climbing, cycling, jogging, marathon, race, rave, mtb or even being used as a daypack or bookbag for school.