Creality includes a set of Allen Wrenchs with every 3D Printer. A 4mm, 3mm, 2.5mm, 2mm and 1.5mm allen wrench.

This is a holder for the Allen Wrenchs and It slides into the top aluminum extrusion.

I used some of the T-Handles by garygrano https://www.thingiverse.com/thing:4912677 I included garygrano .stl files for the 4, 3, 2.5, 2 and 1.5 as well in the download.