The Evolution 4 messenger bag is a versatile, slim-profile case that converts from a camera bag to a briefcase. Up to one DSLR with a lens attached, a flash, and 2 to 3 additional lenses (including a 70-200mm f/2.8) can be protected inside the foam-padded compartment called the "shuttle", which features adjustable, foam-padded dividers.To convert it to a briefcase, simply remove the shuttle from the bag using the handles. The main compartment can then be filled with files, paperwork, or other necessary items. Since the laptop compartment is part of the bag, a laptop can still be carried. To convert it back into a camera bag, just slip the shuttle full of your camera gear back into the bag.Features:Foam-padded Computer Compartment - Behind the shuttle is a foam-padded compartment that holds most 15.6" screen laptops.Zippered Top - The zippered top opens away from the body for fast access to a camera with a lens attached. Gear can also be accessed by unbuckling and lifting the top flap.Pockets for Accessories - The front zippered pocket has paraphernalia pockets to organize discs, business cards, a phone or iPod, pens, pencils and other items. A zippered pocket on the front flap is perfect for keeping keys and tickets readily accessible. The sides have a mesh pocket for a water bottle and feature Tamrac's Modular Accessory System attachment slots to customize this bag with Tamrac's optional accessories. A zippered back pocket stores a notepad or magazines. Carrying Options - Soft, foam-padding in the back provides cushioning while the shoulder strap allows the bag to be easily swung from back to front. A carrying handle lets you grab the bag quickly and Tamrac's Piggy-Back Pocket allows the bag to be easily slipped over the handle of rolling luggage.