On rugged and tight trails, the 3400 Southwest is a flexible performer that can adapt and handle the way gear volumes change for weekend, section, or thru hikes. Ideal whenresupply points are less frequent and/or for equipment flexibility is needed. When the extra volume is not in use, the 3400's top can roll down enough to make the overall size of the pack similar to the 2400, but that additional space can come in pretty handy when you need it.? When the route is thick with vegetation, requires the occasional up and over immovable objects, and calls for suck in your gut and shimmy through type moves, the Southwest is the backpack you want up-close and personal. This pack family is made specifically for tough adventures that would rip most other ultralight-style packs to shreds.