The external shell of the bag is made from high quality heavy-duty nylon, coloured dark grey and blue/green. It is shower resistant, and comes with a slip-on rain cover for extra protection against the elements. The bag comes with a few accessories, including two mesh bags with Velcro patches that can be attached anywhere in the main compartment, and a handy tripod holder, which is can be attached to either the front or sides of the bag via a system of straps and hooks. It can accommodate even quite large tripods, which can be secured to the bags many loops with straps that are also provided.
The R-106 is designed to carry heavy loads, and to that end it has a very well designed and extremely comfortable adjustable harness system. It has a wide, stiff and well-padded hip belt to take most of the weight, and fully height-adjustable shoulder straps. It also has a chest strap to help keep the weight well balanced. This too can be adjusted for height, but I would have preferred it to also be elasticated like the straps on the better hiking packs, since this makes it easier to breathe freely. Also located on the shoulder straps are two loops for attaching a camera. The R-106 comes with two straps that attach to your camera and clip into these rings, useful if you're carrying a large and very heavy pro DSLR. The straps are compatible with Kata's a excellent reflex E camera strap.
One additional feature of the bag's design is the facility to insert a specially designed optional trolley with an extendable handle into a sleeve behind the harness, turning it from a rucksack into airport luggage.
I've taken the R-106 out on several long walks across Dartmoor, loaded with two DSLRs with lenses that I'm testing at the moment, plus my own DSLR and lenses, and a large professional tripod, for a total weight of about 25kg. I found it to be extremely comfortable to carry even when fully loaded and walking over rough ground. Most of the weight is supported by the hip belt, reducing fatigue and promoting a good natural walking posture. The only real problem was the position of the tripod, which had to be removed from its straps whenever I wanted to get something out, although to be fair this is nearly always a problem with camera rucksacks.
The Kata R-106 is a well-designed and well-made rucksack for larger professional camera systems. It offers a very high level of protection against shocks and adverse weather, and even a certain amount of crush protection. Its excellent harness system makes light work of heavy loads, and the provided accessories add a further level of versatility that will suit any need.