This controller will adjust the speed of your fans and has 5 step transformer that ensures there is no electrical noise, buzzing or humming when you fans are running at a lower speed unlike other controllers. This in turn makes it work very well with acoustic and large fans. It will keep you room within +/- 1 degree of your set temperature.We recommend that you're outtake fan is about 25% more powerful than you intake fan to create negative pressure in your growing environment. The SMS hybrid controller comes with a 5mt NTC temperature probe. The SMS hybrid controller can be used with just one fan if you don't wish to use two. Both fans plug straight into the SMS, there is no need for any extra wiring. Comes in either 4 Amp, 8 Amp or 16 Amp
