This is a nice and simple design, it is a replacement round foot for the Boonton range of test equipment.
It is 24mm in diameter at the widest point and 16mm high just like the original feet, I have also added a 20mm high version in case it is needed.
The original feet also have a metal insert that the screw/bolt passes through, its not really needed, I think they did it to screw down onto the metal insert rather then onto the plastic, don't over tighten and you should be fine!
Creality / Generic PLA
Black (to match OEM)