The Classic Series - The Wachusett belt comes with 10oz. bottles. The elastic webbing is comfortable and form fitting. The pocket is built right into the back of the belt and is spacious enough to carry your smart phone, ID and nutrition. This design has ben the most widely used hydration belt in the world, which means there's a lot of history here. Fuel Belt has won more major events around the globe than all of their competitors combined. A proven favorite amongst runners of all terrains. The classic collection was first launched 13 years ago. To celebrate the last decade, Fuel Belt has upgraded to their latest revenge plastic molded holsters. These allow for super easy bottle entry and exit, taking this classic to the next level of performance.