EDIT: I've updated the model to have better hole support for the roof around the central locking pin. I've also uploaded the .STEP file version for easier editing if people need it. This is a reproduction of the tool free hard drive brackets that come with the Cooler Master N400 case. The case only comes with 2 pairs of these brackets even though it supports at least 7 HDDs.

I designed it as a print in place part so that the twist-lock mechanism would be captive. This does mean that it requires supports, but because the bottom face is flat it's easy to remove the supports and smooth out any rough bits.

I suggest printing them in PETG at a 0.2mm layer height.