This is a mount for the Garmin Varia 715 light for mounting directly to the seatpost.   Needs a separate insert from k-edge (K13-504 https://k-edge.com/shop/computer-mounts/garmin-mounts/replacement-garmin-insert-kit/), and a single M5x18mm cap screw for the seatpost clamp.   

To keep things simple, you'll need to remove your seatpost and slide this mount on before clamping down.   The threads for both the M3 screws that come with the k-edge insert, and the M5 clamping screw are modeled in the design.   I used blue loctite on the insert screws for a little extra strength.   Be careful not to overtighten.

I'll also post the file for the 72.5 deg. 27.2mm seatpost version and a 72 deg 31.6mm seatpost.

Enjoy!