The Tri Backpack L provides 3 ways to store, carry and use your gear. You may use it in the backpack, sling bag or "X" position. Suitable for your pro DSLR with battery pack and attached long-range zoom plus 5-6 additional lenses, flash and accessories; media card storage and space for 15" laptop.The unique design of this pack allows you to access your gear even with the traditional backpack shape. In the backpack or "X" position with the straps across your chest you can easily and quickly swing the pack to your left or right side by simply releasing the quick release buckles. This means you don't have to remove the entire pack to retrieve gear.