Carry all of your small essentials when youre out running including gel packs, gloves and more with the Nike Running Waistpack. It has a contoured, lightweight design and secure adjustable belt for your comfort and less bouncing as you run. The expandable stretchy mesh pocket is perfect for holding your small essentials and it closes easily with the easy single-button, buckle closure. Contoured, lightweight design and secure adjustable belt for comfort and less bouncing as you run. Expandable stretchy mesh pocket to hold your small essentials & easy single-button [buckle] closure. Composition: body:60%nylon,40%polyester, lining:100%nylon. One size. Keep away from fire.