Review on 💨 upHere U1204 120mm USB Fan with Adjustable Wind Speeds - Ideal for Computers, PS4, TV Boxes, and AV Cabinets by Kyam Deriphonse

Fans don't move much air, but they're quiet and run with Roku's USB source and wireless router. Airflow is weak, but meets the need to keep the device's temperature low so it's inaudible. Not worth getting speed control, the difference in airflow and noise level is negligible and really not worth the cost and probably adds a point of failure.