The Lowepro Flipside 500 AW is built to protect, store and carry a 500mm f/4 lens, plus addition pro-sized equipment in a padded and spacious main compartment. An adjustable divider system makes it easy to organize gear in a variety of configurations. An unique back-entry design offers easy access to gear when the waist belt is secured and the pack is rotated to the front and unzippered. It also provides extra security when the pack is worn. A contoured shoulder strap with padded waist belt evenly distributes weight and provides exceptional comfort.