The Delta BreezSlim SLM50 is a compact-sized, low noise, valued priced ENERGY STAR qualified fan. Perfect for single home retrofits as well as large multifamily projects. UL listed for both ceiling and sidewall installation. Fits inside a 4" wall. Air flow of 50 CFM with loudness rating of 1.0 sone. Features a DC brushless motor for extended reliability and low power consumption. 6.4 Watts with efficiency rating of 8.9 CFM per Watt. ENERGY STAR qualified and HVI certified.