we call them door knobs but they are not. these are west german made glass purse latch closeures from the 1920's or so. they come with the attched screw as shown which can be removed. the ball itself is about 1" round and has a variety of uses. although it is not a bead (no hole) it has beeen used for lamp fineals, jewelry box drawer pulls.and also keepsake box feet. available by the each get one just for fun.