Hot check nylon. far-from discreet dualtex. and dependable 600d polyestercombine to create this pumped up piece. This pack keeps you connected to youriPod or mp3 player with its 3-button. elektex smart fabric controlconveniently located on the mono-strap. Turn volume up or down simply bytouching the control on the strap. Plug in your headset of choice via theuniversal headphone jack. also on the strap. and tune in! Fully lined. its zipcompartment in front has a plethora of pockets for a phone. cards. pens andaccessories. and a mesh pocket on the side. Tuck your wallet in the hidden zippocket on the back. Its main compartment opens ultra-wide. Tune in and takeoff! Required 2 AAA batteries (not included).