We have a room with an indoor remote sensor for a thermostat for which the cover was missing. As far as I can tell, the model of the sensor is C7189U1005 from Honeywell.
My cover replacement has pockets for the clips to snap in and rests on the little corner posts to ensure air flow to the sensor. It does have a little bit of vertical play but it fits well enough that I don't think it needs adjustment.