Details The Nathan Vaporswift 4 Liter Race Vest Men's is a more compact race-day version of Nathan's award-winning VaporAir pack, designed with the same AdaptiveFit™ system mapped especially for a man's body. Nathan's progressive fit system allows the vest to adapt and conform to your body whether you are in motion or experiencing size and fit changes between seasons. Offering one of Nathan's excellent performance-and-comfort-oriented soft synthetic blends, the Vaporswift is lightweight, breathable and chafe-free, invaluable qualities in an accessory of this size, and includes enough secure storage pockets to help keep your bounce in your feet and not in your pack. Material 20% Nylon, 80% Polyester Fit Adjustable AdaptiveFit™ Sizing System offers perfect body-mapped fit for all men's bodies Vest fit is snug and sizing tends to run small - size up! Lightweight and comfortable Details Includes 1.5L hydration bladder Two storage pockets on the side fitting up to 22oz bottles Large main storage compartment One back kangaroo pocket for essentials and more No bounce, chafe-free breathable materials Secure front shoulder zippered pockets 360 degree reflective for runs in low visibility Transparent zippered pocket for quick viewing Capacity: 244 cu in/4 Liters Weight With Bladder: 10.68 oz/302.9 g Without Bladder: 6.87 oz/194.9g Nathan VaporSwift 4 Liter Race Hydration Vest