I'm not a rabid fan of the Bear Grylls reality shows, but I've watched enough of them to know that Bear is not bee-essing me when he talks about survival equipment. I'm fairly hard to bee-ess on this subject, having been to USAF Land Survival School up at Colville, WA for two weeks in the late Fall, back in the 1980s. At the School, students are put through as close to actual survival conditions as can be arranged without physically killing and wounding them (it was rumored that in the Navy version of Survival School, they actually could wound you as long as it was a recoverable-to-duty wound).
Your #1 survival tool is your brain, always. Not your gun, not your knife, not how much paracord you have, it's what's between your ears, because that gray matter contains the knowledge, the applications, and the will to survive in a hostile setting with minimum equipment. The brain has to be there, the brain has to be tuned up and the brain has to keep you going through the adversity.
If the brain is there for you, the next most important thing in wilderness survival is your knife. In the School, we were given only what would have been with us on our silk letdown from the crippled bird to our present situation in the deep woods hard by the Canadian border. We made everything from the materials that a successful ejection and parachute landing would have given us. Those idems were our "peter pocket" knife, a 2.25" blade switchblade with a cord-cutting blade as well, the parachute, the parachute harness and back-carrier (with it's huge supply of paracord), the survival manual, small pen-knife and fish hooks in the chute carrier. That, plus the clothes on our backs, was what we had. We spent days learning to make that gear into a comfortable tent, make weapons, use those weapons, find food and catch/kill it, and prepare it. Then we spent 3 days trekking across the Cascades 25 miles while an OpFor force of PJs (same training as SEALs) looked for us. If you didn't successfully evade the PJs and make it to your destination, you failed the course and started over. Yours truly made it, and so did my entire class, all 32 of them under my command, with only one "capture point" (we were each allowed two points, the third busted you). I had this excellent record of my command because God gave it to me: there were 4 USAF Combat Air Controllers (PJ training) assigned to take the course for some reason, and I assigned them as scouts on the trek. They easily detected all the ambushes and kept us out of them.
None of us had a decent knife, though, and the PJs told us that such a good knife made all the difference. Most of them carried a USMC Ka-Bar fighting knife in their kit, but we didn't/couldn't have them in the School.
I picked this Bear Grylls knife because it is big enough to kill with, stout enough to do all the things Bear teaches us to do with a knife, but small enough to carry as something less than extra burden when you're moving, which you do, most of the time, in a survival situtation. It comes with a good Kytel sheath which is adjustable for belt carry through 90 degrees: you can carry it streamlined with your belt or 90 degrees to the belt. Minor fiddling with a hex wrench to do this. The knife also comes with a small, folded survival guide. It does not appear to printed on waterproof paper like the on in the USAF parachutes is. The knife has a thick blade, a Bear Grylls necessity. You want to be able to hammer with a hardwood club or baton on the back of the knife to cut heavy stuff, and your thin-bladed folders can't take that abuse, which is why you have a thick-bladed sheath knife with a stout ridged back of the blade like this knife.
My photos of the knife:
As packaged. Belt loop is on the other side.
Out of sheath with ruler for size comparison:
The mini-manual of survival which comes with the knife (no, I haven't read it yet)
Golf pencil for comparison of size:
For $35, it's a good addition to my survival vest. YOU have a grab-and-go survival vest don't you? The purpose of that vest is to have all your WALKING S.H.T.F. stuff in one place. That vest has shelter, first-aid, food and a firearm as the basic necessities, and other stuff as you want to burden yourself. I also carry one of these knife sharpeners (best in the West!), plenty of paracord and fire starting materials.