Biqu B1 tool holder, can be attached with spare m4 tnut & bolt provided with the machine, although it is not really necessary. Print in PLA. May fit other printers with 2020 extrusion profiles.
idea taken from https://www.thingiverse.com/thing:3882549 by nanogennari
includes fusion file for further tinkering
The author hasn't provided the model origin yet.