The adapter is to mount a single E3D V6 and a Nimble to the D-Bot.
This will go on the only real, original and true "D-Bot Core-XY 3D Printer",
https://www.thingiverse.com/thing:1001065 from the one and only great Spauda01.
It is developed together with Darkarchon.
There are two versions, one with mounting points for a 50X50 radial fan, and one without. This is the version with the mounting points for the radial fan.