The one-hand operation is, of course, already given the size, not so easy.
Since you need to grasp the handle at the front, you have to watch that you look at. With the ausklappenden, rotating guard, not the hand / finger clamps
The best way to a 2 finger operation used to: while turning the thumb on the button and one-handed with his forefinger the guard.
But all in all a great knife for the collector, 5 stars!
Just FYI:. So-called knife, which can be opened with one hand and lock, are since 2008 to carry out a general prohibition! This does not depend on length of the blade, or others - that only for those who want to drag the knife to "self-defense" with it. They should be doing it with a switchblade knife with max. Procure 8.5cm blade, because they are (still) to carry with them allowed (yes, we have in D sooooo great gun laws) ...