Make your morning run easier and more comfortable with the Nike Running Transform Vest Pack. Made with lightweight fabric and a form-fitting, apparel-like design, this vest pack ensures maximum comfort and breathability. When not needed, this vest pack can fold away into its own integrated waist pack with a zip pocket for a better running experience. Take your running to the next level with the Nike Running Transform Vest Pack. Nike Running Transform Vest Pack features: Adjustable chest and side straps offer a customized and stable fit. Multiple stretch mesh pockets enable easy storage. Safety whistle on the vest front comes in handy during an emergency. Body: 94% polyester/6% spandex; Lining: 82% polyester/13% nylon/5% spandex.