Are you refering to the conductor going "straight" into a "hole" at the back of the device, and then you tighten the screw which compresses the "hole" tight??
That may be a very poor choice of words, but I call those devices "spec" grade. They are available here, and they are more costly than the binding screw post, and the back stab devices. I like them, my men like them, and we use them most of the time. Ya get what ya pay for.
Those are the good ones. The crappy ones have a little spring clip inside to grab the wire. The screws on the side don't do anything here. Imagine the small amount of contact from the wire to the device, similar to that if a pair of wires are touching in one spot only. That small contact area can get really hot. Also makes for lights dimming and staying dim when a heavy load switches on.
