programmable fan controller, 3 speed, auto and manual mode, override mode,24vdc power supply TR3100FAN Programmable 3-speed Fan ControllerFeaturesTo control 3-speed fan only ... : 1 x NTC built-in temperature sensorOutput: 1 x 3-speed fan, max 200wattsAmbient temperature: 0 °C [+32 °F] ~ +45 °C ... clock only)Battery life: > 5years (10 years Maximum) programmable 3-speed fan controller