The F52 has a blend of some of the most popular features of our tactical packs: combined top-loading and barn door front-loading access, interior organizers including back wall PRC-117 radio compartment, PALS/MOLLE compatible webbing, full-length tubular side pockets, an LP-1 compatible top flap, a built-in rain cover, and more. This combination makes a really great, robust, highly organized mid-sized pack.Like the Warhammer, the Jackhammer is built around the U.S. military's beloved ALICE, a tried and true pack frame. Using the frame as a core structure, we've developed an entirely new style of pack that has amazing utility and versatility. It takes advantage of the ALICE's compact size, and take-anything-you-can-throw-at-it toughness, and incorporates features and qualities that have made Eberlestock packs famous. Our original approach to embedding the frame inside the structure of the pack creates a super quiet, tough, body-riding pack. Because the frame is fully wrapped in the structure of the pack, more along the lines of an internal frame than an external frame, we've eliminated frame noise, and built an exceptionally quiet, comfortable and well ventilated field pack. The Jackhammer's interior features start with an amply sized storm collar, which allows you to over-stuff the pack. Next, a back wall radio pocket with second pocket and cinch-strap, two plastic-mesh zippered see-into pockets, a ring of translucent pockets around the bottom tier of the pack, and a generous matrix of MOLLE on the inside of the front door.