ApplicationsDual 120mm computer fans with ac plug circulate the air for greenhouse, rv refrigerator, diy meat dry-ager, small gas heater; Exhaust odors/solder fumes/steam/cigarette smoke; Boost heating/cooling to rooms; Cool server rack, mining rig, AV cabinets, pet houses; or ventilate basement, attic, garage, bathroom window Infinitely Adjustable Speed Features a variable speed controller with power switch allows you to adjust the fans speed to optimal noise and airflow levels for various applications and noise environments; start voltage: 4 volts Powerful Booster Fanlifespan 50,000hrs, This register booster fan features durable focused-airflow blades and brushless motors dual ball bearing, high static pressure allows the fan to push (or pull) air efficiently, even in restrictive spaces Ready to use Out of the boxDimension: 9.45"x4.72"x1.5"; 1.64ft fan cable and 7.7ft controller power cord; Just plug into 110v/12