The SMSCOM Smart Controller is an easy to use plug and go compact fan speed controller. It has an excellent 5 year guarantee and an impressive 5 amp current, which coverts to 1150 watts maximum capacity. The temperature probe takes constant readings and adjusts the fan speed accordingly. There is also an override minimum fan speed control which lets you set the lowest speed the fan will run. There is also a temperature control dial for you to set the desired temperature of your growing environment.