1.[Powerful fan 120mm]standard 120mm Computer fan, running speed is 900rpm to 3000rpm, generating a constant and continuous flow of air keeping everything cool and temperatures down and if there is a need for more air flow the included dial controller allows you to increase the air flow 2.[Controllable Speed]Allows you to vary the voltage / speed of the fans.you can adjust the fan's speed to optimize the airflow and noise for your application 3.[ Fan IP67]its designed to withstand the humid/dust-exist harshest outdoor environments; Keep your equipment runs smoothly without worrying about rain, splashes, dusty conditions, or brief submersion 4.[Plug and Play] The speed controller has a standard two prong wall plug feeding a power supply. enables the fan to be powered through an AC outlet; Just plug it into a socket and start the fan