Needed to make some key holders for a small lot of padlock keys for two buildings at work so mocked this up so it would use less material than most others on thingiverse and allow me to clamp it onto multiple benches/work surfaces, has a size of 20mm opening so if its smaller than that it will clamp on.

keyring size is 18mm but can hold larger ones if overlapping

uses metric M8 screws so if you have some you don't need to print them i've included them in a separate file.

make sure you do Fine setting not fast or normal or screws won't work, don't put support inside screw hole it doesn't need it and can break the print.