The CFP-90 is the Army's answer to the internal frame packs so popular with civilian hikers. It is the designated cold-weather, expedition bag for infantry and special forces, and has a very generous volume of nearly 8,000 cu in, plus optional strap-on "patrol" packs. Based on my own experience, the CFP90 can haul at least 65-70 pounds of gear with relative comfort and stability.

It features a large center compartment, with radio pouch; two roomy pockets on the left side, and a large single pocket on the right side, with antenna storage capability, are all externally accessible. There is also a special sleeping-bag compartment at the bottom, also accessible from the outside. It can accommodate very bulky bags, as it is designed for the "modular, cold-weather, sleep system" reviewed elsewhere.

An optional "patrol" pack may be strapped on to the top, which adds additional capacity and can be used as a simple rucksack for day hikes or recon duty or whatever you need to do! Numerous ALICE attachment points, straps and buckles make it a flexible system to meet your needs.

The heart of the unit is the internal frame/suspension system. Two flexible aluminum stays run longitudinally the length of the main pack, to which attach the tops of the shoulder straps by way of an adjustable mechanism. The waist strap is padded, especially in the kidney area, and uses a large quick-disconnect buckle. Padding is everywhere, and thanks to the mesh back design, it is not too hot on your back.

All dimensions are adjustable, which is a good thing as it is not easy to make one of these comfortable without extensive "tailoring" to your physique and load. Once established however, it is well-balanced and easy to carry. The load is effectively transmitted to your waist, and--if properly packed--is centered over your hips, so it doesn't pull you to the rear as frame packs often do.

Construction is solid, using that rain-resistant nylon you see everywhere, and mine has held up pretty well despite some heavy use. The bag is said to be water-resistant, but if you want to make sure, use a few of those waterproof bags made for the old ALICE packs and rest easy.

Addendum:

I busted the shoulder harness on my m1990, and it wasn't easy to find a place that could fix it or sell me parts. I learned that the pack was designed by Lowe-Alpine, although they do not officially support it. However, Lowe did point me toward http://www.ripstoprepairs.com/ who is an authorized Lowe repair shop. They can fix almost anything, and did a great job on my pack. They will do custom jobs, too, and seem to be familiar with the mil-spec gear.
 

Editor's note:

There are a lot of 'better than mil spec' models showing up for about $80. While we have not yet tested any, it seems a bit too cheap. The real things go for well over $100 used on eBay, so there has to be something that's not as good.