PocketKNIFE

This out the front contraption is Very Definitely Not A Switchblade. Honest! Despite outward appearances -- including that false edge on the back, which is not actually sharpened from the factory due to the usual ridiculous "dirk and dagger" laws.

Note how when the blade is retracted that switchblade-like thumb switch is... all the way to the... rear. Wait, what?

Yes, the mechanism on this is a spring assisted slider. Left to its own devices it will not fire the blade fully out the front, but if you give it a good shove (with a heaping helping of practice and dexterity) it will lock forward with a distinctive hollow sounding thwack. Provided you don't get your fingers in the way of the slider, which is tougher than it sounds. This won't hurt you, but it'll prevent it from locking open and then you get to manually slide it the rest of the way feeling like a chump. A safety lever is provided which locks the mechanism closed, since unlike a true in-out switchblade it's not too tough to fire it off (at least about halfway) in your pocket.

Retracting it is significantly less slick, with unlocking achieved by way of a tiny toggle out on the front end of the handle, mere millimeters away from the blade, which is quite fiddly and stiff. Get that pulled and the blade kind of goes all flaccid in the track. Then you get to rack the thumb switch all the way back down a good four inches, taking up the spring tension in the process.