TRUECFM: Guaranteed Performance no matter how complicated the ductwork. Selectable CFM with speed of 50-80-110, maintains CFM through 0.4" static pressure. Near silent operation, <0.3-0.5-0.6 Sones Save Up to 30% on Installation Time: Easy snap-in housing to hanger bar and slide-and-lock blower attachment. Seamless Design: Blends into the ceiling with CleanCover grille and floating mounted positioning. Slide-Clip Grille/Cover: Fast grille attachment for easy maintenance without the hassle of springs.