Controls high limit and fan motors in forced air heating systems. Three wiring terminal options available for easy installation. Push-in receptacles for stripped wire. Female receptacles for 1/4" male flag connectors. Auxiliary screw terminals. Field adjustable fan and high limit settings. L4064B,W, and R models have a manual fan switch that overrides the fan control to keep the fan running continuously. TRADELINE models with mounting adapters for easy installation and strain relief bushings to protect wiring from field abuse..