This is the new Delta, a production knife made by SureFire. They also make some of the most amazing tactical flashlights in the world, by the way. Everyone, boy & girl, man & woman, needs to carry a knife. I have longed wished that it was a federal law that, upon birth, every baby is issued a multi-tool of some sort, like a Leatherman or even a Swiss Army Knife. How useful would that be to grow up learning self-reliance and resourcefulness through the use of such a handy tool?
My personal pocket knife is a Spyderco SC-16PS Wayne Goddard folder which I have had for several years. It is extraordinarily durable, has a pocket clip, and keeps an extremely sharp edge. Some folks find it a bit large, with a 3 3/8" half-serrated blade, but the reason for that is simple. I have lost or damaged at least half-a-dozen small, normal-looking pocket knives over the years, some of them rather valuable and one of them irreplaceable. But I have never lost my Spyderco, or at least not for more than a day or so, and then I invariably find it in the laundry. Spyderco doesn't make this model any more, but they do make a wide selection of excellent knives. A good friend, Wray Reed, turned me onto Spyderco about 10 years ago and I have been completely happy with this knife.
With knives, the conventional wisdom applies that the good ones aren't cheap and the cheap ones aren't good. If you want a sharp blade, and why would you not, then you need a knife made of some serious steel, not some crappy Pakistani alloy clamped between some cheesy-looking wood-stained handles.
Here is a cool exploded diagram from the Surefire website showing off some of the Delta's practicals.
For more details on this knife, as well as a wealth of great info and pictures on everything knife-related, please visit the Knifeart.com website. It is a well-designed site that features some of the most beautiful handmade, as well as general production knives in the world. If you have never explored the artistic side of edged instruments, you are in for a real eye-opening treat.