WhisperFit 50 CFM Low Profile Ceiling Mounted Fan: * Low-profile housing for smaller ceiling cavities * So quiet you might not know it"s on * Continuous, trouble-free operation for many years * User-friendly installation * Power consumption (watts): 4" duct: (15.0 at 0.1" static pressure, 14.7 at 0.25" static pressure), 3" duct: (15.0 at 0.1" static pressure, 14.8 at 0.25" static pressure) * Energy efficiency (CFM"s/watts): 4" duct: (3.3 at 0.1" static pressure, 2.0 at 0.25" static pressure), 3" duct: (3.3 at 0.1" static pressure, 2.1 at 0.25" static pressure) * Speed (RPM): 4" duct: (637 at 0.1" static pressure, 932 at 0.25" static pressure), 3" duct: (741 at 0.1" static pressure, 978 at 0.25" static pressure) * Duct diameter: 4" (3" with adapter) * Mounting opening: 10-7/8 sq in * Dimensions: 5-5/8"H x 10-1/4"W x 10-1/4"D * Weight: 11.22 lbs