The Expandable Trek Backpack provides amazing storage space and versatility for the active, urban professional. This ergonomic backpack features multiple pockets and an expandability option that accommodates an additional 20% – this case support s all of your essential items for work and play. The front organizer pouch includes multiple pockets for your cell phone, pens, AC adaptor, etc. It also features a recessed mp3 player pocket that sits flushed on the backside of your backpack!