ROPTAT Hydration backpack sets When you are out on the trail, timely replenishment of water is very important. This hydration pack comes with its own 2-Liter hydration bladder and so much more! Its design is simple and stylish, and it is very convenient and comfortable to use，you can drink by simply biting the mouthpiece instead of water bottle, while your other items can also be stored in the backpack. You'll get the best fit with the adjustable shoulder, chest straps. Shock-absorbing chest strap works with the rest of the harness to reduce bounce. Take it hiking, cycling, running, and anywhere you may need a bit of gear and a lot of on demand water,the ROPTAT Hydration Backpack is your prefert choice for outdoor sports. STRONG AND DURABLE SHOULDER STRAP High quality waterproof nylon fabric.resistant to abrasion, wear and tear.reflective webbing design makes your night trip safer,The strap and fabrics are durable and can carry the weight of 20KG. THICK INSULATED LAYER This cycling hydration backpack has an insulation compartment made of thick aluminum foil,which can hold a 2L water bladder and can be liquid cooling for up to 4 hours. The best hydration pack for running, hiking, cycling, or biking. COMPACT& LIGHTWEIGHT Mesh and poriferous EVA design on the back for maximum breathability and heat dissipation.Low-profile, perfectly built for lightweight pursuits like running, road biking and ultralight hiking. They feel light and stable on your back and won't create any wind resistance. 2L Water Hydration Bladder Bag if you want to keep drinking,when you are Hiking Biking Camping Climbing Cycling Running,Our water bladder for hydration pack is made from Premium Ultra-Durable EVA which is tasteless & BPA free,that is your best choose. As the most popular design for high end hydration systems in recent years, this allows you to refill in any condition. High flow, auto-lock mouthpiece to prevent leaking and comes with dust cover. HYDRATION BLADDER BPA FREE MATERIAL WITH LARGE OPENING LEAK-PROOF MOUTHPIECE ON/OFF SWITCH WITH DUST COVER