IIRC its an ATR Fan Revision Kit. I believe the kit originally came with an electric module that replaces the stock high speed relay and it's designed to switch the fan on immediately after start up. Once the car reaches a traveling speed of approx. 30 - 40 mph, the fan will shut off via the "airflow pressure switch" mounted behind the grill. Old school tech for sure. Mine is still in use . Haven't had a reason to remove it yet. Lol.