As written on the Ultraspire website: “The original Momentum’s accessible rear water bottle pockets were very popular among our athletes. The Momentum 2.0’s Fluidic holsters have taken this feature to the next level. These new pockets are more intuitive and easier to access due to the inclusion of a magnetic closure and rail-like system. This design makes it easy for you to reach back behind your hip and grab or stow a bottle while on the go. This minimalist 6 liter vest has been outfitted with UltrAcool Light Mesh which provides a very breathable and lightweight feel and increases pack durability. An upgraded shoulder pocket has been added allowing you to carry any size cell phone. Shock cord has been added to both front strap pockets increasing versatility among what gear or bottles you choose to carry. The main compartment has been modified to a quick stash style which allows for easier access on the go as well as increased capacity. The Momentum 2.0 is Z-pole compatible.” -The vest will also include 2 water bottles. -Still in great condition! It has only been worn a couple of times. Please let me know if you have any questions. Happy to accept offers for this item.