This allows for Ryobi Expand-It attachments to be mounted to the wall. The hangers hang from a piece of DIN Rail that gets mounted to the wall. This allows them to slide. 

The hangers have a key way for the dimple of the attachment to slide through. Once the dimple is through the keyway, the attachment then gets rotated so that the dimple no longer is in line with the keyway and this allows the attachments to hang. The hangers can be installed on the DIN rail in either orientation.

There are 2 different hanger designs, the difference being the rotation of the keyway. This is because the dimple is in different locations on different attachments.