The VestPac GrandPac is the ultimate skiing and snowboarding accessory, when worn under your jacket, water doesn't freeze and your electronics can last 10x as long. With a large zippered pocket big enough to carry a rescue beacon and clear pockets designed to hold a scanable ski pass, you'll be ready for anything. 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.