Nylon Imported UTMOST STORAGE CAPACITY: Backpack size 18.5" x 10.5" x 6". Stay organized with 9 functional divider pockets to keep all your essentials secure. The 18-LITER main compartment is large enough for clothes, notebooks, first-aid kit, pet supplies. Built-in mesh pocket for personal valuables. Exterior upper velvet pocket for protecting glasses, cameras, cell phones. Trekking poles/water bottles fit in the side mesh pockets for easy access. INSULATED BLADDER COMPARTMENT: This hiking hydro backpack has a special separate insulated compartment for the water bladder to keep liquids cool for up to 6 hours (with ice packs), making it perfect for long hikes, bike rides,runs or any outdoor adventures. EFFICIENT HYDRATION SYSTEM: This 18L hydration backpack includes an UPGRADED 70 oz / 2-LITER water bladder made of FOOD-GRADE PEVA material, along with a high-flow bite valve. The mouthpiece cover protects the bite valve against dirt and damage. The 2-LITER bladder is replaceable and supports up to 3-LITER / 100 oz. SECURE YOUR ADVENTURE: The hiking bag features High-Density Nylon fabric and a Built-in Rain Cover - ideal for rainy activities. The reflective strips keep you visible in low-light conditions. A designated space for your helmet between the outer and middle pockets. HIKING/CYCLING/RUNNING/SKIING WITH EASE: This 2 lbs lightweight water backpack features an ultra-elastic 3D breathable padded back, adjustable chest and waist straps to provide comfort and stability for all body sizes. This day pack has got you covered for all your adventures. Embark on your outdoor adventures with the EVERFUN hydration backpack, designed for hikers/runners/bikers who need a reliable way to stay hydrated. Features: Hydration Bladder: Includes either a 2L or a 3L hydration bladder, with an insulated compartment to keep it cool throughout your hike. Roomy Storage: Features an 18L main compartment and multiple pockets for all your gear, whether for a day hike or an overnight trek. Comfortable: Padded straps and a ventilated back panel ensure comfort during Family outings. Durable Design: Constructed with water-resistant materials. Complete with reflective strips for low-light visibility and a rain cover. FAQs: - How to Clean the Bladder? Mix two tablespoons of baking soda with hot water(below 60°C) in your reservoir. Let it sit for 30 minutes. Alternatively, use Cleaning Tabs. - Is the Bladder Replaceable? Yes, you can upgrade up to a 3L bladder. - Versatility: It is perfect for hiking, running, skiing, hunting, trekking, biking, cycling, boating, kayaking, and fishing. Great for: - Hiking trails, where you can enjoy easy access to water without the weight of bottles. - Running, keeping you hydrated without carrying a water bottle. - Skiing or snowboarding, with plenty of space for extra layers and gear. - Fishing trips, with a secure way to carry your water and snacks. - Festival, to keep you hydrated and hands-free while enjoying the fun.