Its remix of a wall mount. I use it for my Metabo PowerMaxx BS 12 Akkus. According to the Lawny (Guy which kindly designed it in triple format), it can be used as well on Milwaukee and Bosch.
I used 2x M4 inserts from honeycomb storage wall.
2/4 nuts M4 and 2x DIN912 M4 Screws (Length, i think 16mm).
The author remixed this model.