This is a spur gear guard which fits the Team Xray XB4 2020 and 2021 models.
It might fit others, check if the little carbon plate that holds the slipper clutch assembly in is the same shape. ‘20 and ’21 models share the same part (#361176) for this.
It prints on my Prusa MK3S without supports ok, there is a little stringing on the underside of the top of the curved section but there is enough clearance above the gear for it to not be a problem.
The author marked this model as their own original creation.