This thing is a set of camera mounts for a GWS S125 1T2BB 360 degree sail winch servo. There are two different sized mounts designed for the GoPro Session or Runcam2 cameras. The mounts attach directly to the GWS servo horn and the cameras are held in place using two zip-ties with optional double-sided adhesive tape.
Note that this design is for the GWS sail winch servo with a 25 tooth spline (there is an older version with a 23 tooth spline)
It is important to print these mounts using fine settings so that the servo teeth come out correctly and grip with the horn. Print slowly with a smaller layer height. Make sure to secure the mounts to the servo with the screw.