Continental Fan Manufacturing SA250 Exhaust Fan N A Accessory Sound Damper 10" Round Duct Sound Attenuator for AXC and EXT Fan SystemsInstall one or more sound attenuators to reduce the operational noise of your exhaust fan system Let us provide all the accessories needed to install an AXC In Line Duct Fan or EXT External Mount Exhaust Fan Continental Fan Company was established in 1986 to manufacture and distribute quality ventilation equipment Their objectives then were simpleÂ... to provide superior products dependable service and competitive pricing They remain unchanged today Features:Fits 10" round ducting