This is a pegboard-mounting holder for the 4x heads that comes with the Milwaukee M12 Installation Driver. It would likely suit the Fein one as well as I believe they use the same mounting/connection style. Hole spacings are 50mm centres vertically (slot centre to hole centre) and 200mm horizontal centres.
The author remixed this model.
I removed the side tabs from the original STP, and added in a flat tab to allow mounting to pegboard with spacing suitable for 50mm or 25mm hole centres. Slightly oversized holes (6.5mm) and the bottom mount hole is a slot in case of any strange spacing on vertical hole centres. Designed to mount facing upwards.