Approximately 450 units were sold in the U.S., plus an additional 200 were sold in Canada. This recall involves L500 series fans designed to circulate air in and out of a home or building. The fans were sold under the following nine brands: Broan, Twin City Fan, Carnes, Acme Eng and Mfg Co, WW Grainger, Captive Aire, American CoolAir, Solar and Palau, and American Coolair Corp. The model information is printed on the specification label that is attached to the blower assembly. See the CPSC notice for a full list of recalled model numbers. Consumers should immediately turn off and unplug the recalled fans and contact Broan to receive a free replacement fan.