An 80 CFM ceiling exhaust fan sized for an enclosed room of up to 90 square feet, this unit clears steam and stale air through a standard 4 inch duct while running at 1.5 sones, quiet enough that it does not disrupt the tranquility of a bathroom. The airflow comes from a multi-blade wind wheel turning at 1200 RPM on a copper motor, drawing 22 watts from an AC 120V 60Hz supply, so leaving it running costs very little. An advanced check valve sits in the path and stops dirty air flowing back down the duct once the fan shuts off, which is what keeps exhausted air from returning to the room it just left. The housing is galvanized sheet rather than plastic, chosen for longevity and continued performance in air that is regularly humid, and the grille is ABS finished in white so it reads as part of the ceiling rather than an appliance. Both Energy Star and HVI certification apply to the unit. Dimensions matter overhead: the assembly measures 11.8 by 9.5 by 6.7 inches overall, the housing itself 7.5 by 7.25 by 6 inches, and the visible grille 9.5 by 8.7 inches, sized to a ceiling opening of 7.6 by 7.3 by 6.2 inches. Duct diameter is 4 inches and total weight is 5 pounds, light enough to handle at arm's length above the head. The fan ships as a single boxed unit.