The DBF 110 Dryer Booster inline fan addresses every obstacle. A silent partner for your dryer. The fan compensates for system duct losses and allows the dryer to exhaust warm moist air as the manufacturer intended. The fans can handle up to 60 feet of duct and six elbows. The backward blades allow lint to pass through the fan. The patented control automatically operates the booster fan whenever the dryer is running.