●The reflective design of the backpack increases visibility in low light conditions ●The shoulder strap has two water bottle compartments to hold 250ml soft water bottles, energy gels and other consumables ●The shoulder strap cell phone compartment can hold 6.7 inch cell phone, with adhesive buckle design to prevent it from slipping out during exercise ●Main bag compartment can hold 1.5L water bladder or carry-on light clothing and other items ●There are two chest adjustment systems, which can be quickly disassembled to adjust the tightness, simple and easy to use