Hi Aardvark, Yes this is only intended for unopened twist off and pop top bottles. The idea is to (somewhat) deter people from drinking your unopened drinks in the fridge. Obviously this being made out of plastic, it could be broken off but that's not really the point. It was really just some random idea I had that I wanted to create. The lock mechanism actually works fairly well considering that everything is 3D printed including the tumbler mechanism. The only non 3D printed parts is a small spring and a small metal rod for the hinge(although this could probably be printed as well).