Blauberg Inline Mixed Flow Fan 4" 62-105 CFM ULTRA QUIET !! Compatible with 4" to 12" round air ducts For ventilation systems requiring high pressure, powerful air flow and low noise level Casing is made either of durable ABS plastic or polypropylene with lowflammability, UV- and corrosion-resistant Special casing design enables easy dismantling of impeller and motor block without air ducts detaching to