These are some leveling feet that use a 5/16" hex nut and hex head bolt, with mounting holes for #6 wood screws. I used these on my portable MPCNC, but they can be installed on pretty much anything. Just rotate the bolt to increase or decrease the foot height.

OnShape File: https://cad.onshape.com/documents/5490839800f5cbfd5633b50c/w/409f26812cfb0c1de4f4f6dd/e/90acbdf3929ef79bbe65f6b0?renderMode=0&uiState=644893a88d70874f3a17af83