UltrAspire Zygos Unisex Lighweight Hydration Ultra Running Pack - 5.0 Pitch Black, Small

ErgoFit - The human body is complex with intricate detail and function. The same attention to detail is present in the design of our packs to enable precise movement, contact, and weight distribution which ensures that there is never any inhibition to the biomechanics of the human body. Insulated Bladder Compartment - Made of Mylar, the insulated compartment reflects and traps temperatures to help keep fluids hot or cold. Reinforced Main Back Compartment - The main back compartment has been reinforced at the stress points with XT fabric which contains stronger than steel ripstop fibers. This pack includes a 2-liter reservoir that fits into the removable insulated bladder compartment. On-the-go Pockets and Compatible Bottles: Featuring 8 on-the-go pockets, there are 2 zippered shoulder pockets, a dual 4-way stretch mesh pocket, a pair of stretch mesh pockets (one of which is zippered and suitable for carrying a large cell phone), a zippered side pocket, and a magnetically closed side pocket. UltraFlask, Formula 250, Human 20 oz 2.0, or Collapsible Bottle (NOT INCLUDED). MAX02 Sternum - The Max02 Sternum is a shock cord securing system that helps create a comfortable & natural breathing pattern while at the same time keeping the pack secure. The shock cord allows for stretch outward and 100% rebound which keeps the pack snug against your body empty or fully loaded with no restriction of movement.