30.5x30.5mm (M3) to 20x20mm (M2) adapter for freestyle quad

When my commercially available, 3D-printed adapter broke, I decided to design my own and make it a bit more solid. The part is designed in the direction I wanted it to fit in the quad, but it should be printed upside down to avoid the need for support under the recessed parts.

Update: I made the original part with recesses suitable for my drone design, but as I realized this would not fit every application, I also made a simple, flat version a bit thinner (2mm), but still a stronger design th