This model is to keep your Creality filament detector when upgrading to a direct drive extruder (I upgraded to Sprite Pro and had a need for it). Mounts next to the top spool holder on the aluminum extrusion with standard T-slot nuts. You'll need to get a M3 tap or heat the stock screws up lightly to thread into smaller holes. the 2 counterbored holes are for the t-nut bolts.
The author hasn't provided the model origin yet.