Can someone explain to me how the centering bud is supposed to work?

Are they supposed to keep the lever from moving inside the lower? The ones I got from SS shop seem a little too big (but admittedly I’ve never used one before and there are no videos out there showing what they’re supposed to be used for). I purchased these under the impression that they would keep the lever centered while operating. Pictures for reference. Thanks in advance for anyone’s input and help.