The installation on this ceiling fan is user-friendly, with a mounting opening of 10.5 inches, grill size of 13 inches and duct diameter of 6 inches. ENERGY STAR® Products that are ENERGY STAR-qualified prevent greenhouse gas emissions by meeting strict energy efficiency guidelines set by the U.S. Environmental Protection Agency and the U.S. Department of Energy. The ENERGY STAR name and marks are registered marks owned by the U.S. government, as part of their energy efficiency and environmental activities. WhisperGreen 130 CFM Ceiling Mounted Ventilation Fan with DC Motor and Variable Speed Controls: * Constant CFM performance * Variable speed control * Delay timer * Quiet motor means quiet operation * User-friendly installation * Duct diameter: 6" * Grille size: 13" * Mounting opening: 10-1/2" * Dimensions: 11.0"H x 14.5"W x 16.75"D * Weight: 12.5 lbs