This is a desk mount for the Fiio K5 Pro, this model can be used for both regular desks and desks with frames underneath (up to 25mm).
All that is required is to screw into the bottom of the desk and slide in the K5 (you may need to take off the feet) whilst pulling the clips outwards.
To print the model I printed it with front (the side that doesn't have clips) on the platform with supports. If you are using the flat variant you could probably print it as is with supports.