The VestPac JacksonPac Hydration Pack is a basic, do-anything, hydration pack. Two front pockets and a key ring make it ideal for snow, dirt, road, surf and anything in between. Lighter and more comfortable than most other hydration pack on the market. They are so slim, you can wear them under your outer clothing layers and the revolutionary 3-D Airmesh adapts to any climate, keeping you cool in the summer and warm in the winter. Convenient chest pockets provide ample storage for your valuable electronics and accessories and the low-profile back panel houses a hands-free hydration system. The form-fitting, athletic design guarantees maximum comfort, durability, and style; while heavy duty elastic straps ensure a perfect fit for all sizes.