The files include just modified versions of the base for Garmin in three variations: Basic, 90-degree angled, and Garmin Duplicator. The rest of the files are in the original model https://www.printables.com/model/156670-3d-printing-friendly-garminwahoo-interface
The author remixed this model.
This is the base for an adapter between Garmin and another device. It uses the 1cm-uni-mount system, which consists of two holes spaced 1cm apart, allowing you to easily attach a different type of holder and thus create your own combination of connections.
See more at https://www.printables.com/cs/search/models?q=tag:1cmunimount or www.1cmunimount.com.