1.5L NATHAN x HydraPak QuickStart Bladder with Push-Pull Bite Valve for easier drinking and removal for cleaning; Designed with adjustable front and side straps to comfortably fit a wide range of body types; Four expandable power mesh pockets on the front straps; Large back pocket and separate bladder compartment with hook and loop keepers; Rear elastic bungee cord provides additional storage; Rear stretch mesh pocket fits layers, gear, and larger essentials, plus an elastic pole keeper; Reflective details enhance visibility in low-light conditions