The Flex-A-Lite controller brings the fans on at 60-percent speed when it hits the preset point. The preset can be set from 160-240 degrees. The controller features override inputs for A/C, fan-on bypass, and fan-off bypass so no matter where you wheel you can override the automatic controls if you need to. The kit includes wiring and we mounted the control module high and dry on the firewall. Because of the way we routed the wires, we had to extend the temperature probe wires. If you end up having to extend yours, make sure to solder the connection because the turn-on/turn-off set points are resistance-dependent.