Panasonic WhisperComfort Spot Energy Recovery Ventilator (ERV) offers a revolutionary way to provide balanced ventilation with a ceiling insert ERV. Ideal for a single room, the Panasonic FV-04VE1 WhisperComfort Spot ERV Ceiling Insert Ventilator provides a low rate of continuous air exchange. This insert supplies fresh air to replace exhausted air helping to balance air pressure within the home. Panasonic WhisperComfort spot ERV uses two 4-Inch ducts, one duct to exhaust stale air and the other to supply fresh air from outdoors. With a .8 sone level and rated 40 cubic feet per minute, its low rate, continuous run ensures chemicals such as volatile organic compounds and other pollutants from cleaning fluids and building materials are vented out and replaced with fresh air. This item is compatible with Panasonic FV-WC04VE1 Wall Cap with Styrofoam adaptor that conveniently allows both supply and exhaust air to pass through a unique Y-shape chamber and wall cap through a single 5-1/2-Inch exterior penetration. The Panasonic FV-04VE1 WhisperComfort Spot ERV Ceiling Insert Ventilator with Balanced Ventilation and Patent-Pending Capillary Core is covered by a manufacturer warranty for period of three years from the date of the original purchase and is sold one item per package.