Opolar sells a variety of fans. TheF511is a 9’’ diameter, three-blade desktop model with two speeds and a built-in stand. It can be useful in remote-recording situations or anywhere you have 200–600 mA of current available from a USB Type A port. (I mention this because most USB hubs have an output limit, and on low speed, theF511pulls about 200 mA. On high, about 600 mA.) The fan is driven by a 5 V brushless motor and is advertised as being “whisper quiet.” On low, it is virtually silent. I purchased two units for my mastering desk, placing one at the bottom of the gear bays to direct cool air up through the rack. The built-in stand features rubber anti-vibration feet and allows 360° rotation of the cage. During an on-location test, I was able to power the fan via my laptop just fine (but I could have taken along a USB battery pack or USB power brick for the fan). The slow speed kept the gear cool and did not contribute any ambient noise to the recording. If the 9’’ fan is too large for your application, the company also sells several smaller models. Just remember, you’ll need to supply the USB power; but these days, that shouldn’t be an issue.

$22;www.opolar.com –Garrett Haineswww.treelady.com