Buck Redpoint
The Buck Redpoint has no spring to open or close the blade.
There is a thumb latch (or release lever if you prefer) that holds the blade closed and, after you open it, holds the blade open.
The round "toothed" edge at the back of the blade is used to rotate the blade open with your index finger while holding the latch open with your thumb. This mechanism is called "SafeSpin" (tm).
This thing here ----->
--------------------
It's actually quite simple and kinda nifty.
Now, if I could only get them to make it
without the stinking serrations, I'd buy two or three.
Unfortunately, most of their "outdoor sports" knifes have combo blades.
I managed to get a Short Revolution with a plain edge. Nice blade, by the way. Not properly a "folder" because it doesn't "fold shut" but rather the blade rotates into the handle and the carabiner/bottle opener rotates out into the position formerly occupied by the blade.
Thus, the knife closed is almost the same length as the knife open. Not terribly pocket friendly. Actually meant to hang on your gear by the carabiner clip. You can hang it from a belt loop, but then it's flopping around.
This is the one I have:
This shows the open/closed positions: