The Hampton Bay No Cut 50 CFM Ceiling Exhaust Bath Fan is a very quiet ENERGY STAR qualified ventilation solution. With very quiet operation of 1.0 sone, the Not Cut is among the quietest bath fans available while using 65% less energy, on average, than standard models. The modern-style white grille is perfect for any bath or powder room application. The fan is UL Listed, and fits 2 in. x 4 in. ceiling construction. Duct with 3 in. round ducting.