This baseplate is compatible with euro-style sheet metal pegboards that have 4mm holes spaced 12mm apart. The baseplate is mounted with pegboard / sheet metal screws such as these. 

I was concerned with the questionable sturdiness of other designs, and can happily report that my prints of this model (Prusament PLA, 0.6mm nozzle, 0.15mm layer height, 15% gyroid infill) can carry a couple of kilos without breaking a sweat. I didn't care to test the actual limits. I am using PLA due to the stiffness of it, but would recommend to use a better material if you intend to use it for heavier loads, as PLA would probably start sagging over time.

The mounting holes in the baseplate have some allowance to allow for slightly different hole spacings, and successful mounting on pegboards with sloppy manufacturing tolerances such as mine. This should ensure that you can chain several of these together seamlessly by adjusting the position of the baseplate slightly from side to side, if either your pegboard or print isn't accurate.