Features1The backpack\u0027s reflective design enhances your visibility in low-light conditions. 2Two water bottle compartments are set on the shoulder strap, which can hold 250ml soft water bottles or energy gels and other supplies. 3The shoulder strap mobile phone compartment can hold a 6.7-inch mobile phone, with a sticky buckle design to prevent it from slipping out during exercise. 4The main bag compartment can hold a 1.5L water bladder or carry-on lightweight clothes and other items. 5There are two chest circumference adjustment systems, which can be quickly disassembled and adjusted for tightness, simple and easy to use.SpecificationDesigned for outdoor enthusiasts, this hydration backpack features a 1.5 liter water bag compartment and two water bottle bin, making it versatile for a broad spectrum of users. Whether you're a casual visitor at amusement parks orprofessional athlete, this pack is tailored to meet your hydration needs.Specifications:Material: Nylon, polyester, spandexSize: 38*20*3cm/ 15*7.9*1.2inWeight: 170g/ 6ozPackage List1 * backpack