Step Transformer controller is specific in that the fans are not a noise (howling) at low speed. Step transformers determines the speed of the fan alone using a 6-degrees up / down depending on humidity and temperature. The temperature and hysteresis (sensitivity) can be set on the two buttons, as well as humidity and moisture-hysteresis of the other two buttons.The controller is waterproof housing compatible main contact and 4m cable with a light sensor that detects day / night time, which makes it the perfect controller
