This is a quarter turn / garmin reverse mount to mount accessories to the underside of bike computers. The reverse mount allows the attachment of lower-profile lights or go-pro mounts as quick releases, instead of having to faff with bolts.

I printed with PETG / PETG CF with a layer height of 0.12mm and 3-5 walls + 20% infill to give enough strength to survive road / gravel riding. Additionally (depending on your slicer) printing with “make overhangs printable” helps to print the slots that do overhang the mount. I added a chamfer in the model to help, but your slicer may require supports to print correctly, especially with PETG. That being said, a slow speed is always your friend, especially for a part of this size.