The Airport Commuter photo backpack holds a substantial amount of equipment, including a 400/f2.8, but most importantly still comes within international airline carry-on limits. It also holds a 15" laptop and 10" tablet in separate compartments. Extra security when taking the bag through crowded spaces is assured with a pull-out cable lock and locking YKK zippers. The harness has lumbar support and mesh panelling to help keep your back cool, and the included waistbelt can be substituted with a Think Tank Pro Speed Belt or Think Skin Belt for more support or extra capacity.