Reton 80 Fresh Air Ventilator - Adjustable Passive Make-Up Air Vent. Bring in fresh air from the outdoors and provide makeup air for mechanical ventilation system. The introduction of fresh air from the exterior provides the make-up air to replace air being exhausted by an exhaust fan. Thus, indoor relative humidity levels are kept to acceptable levels and a healthy atmosphere is assured. Fresh air vents protect from excessive negative pressure in the living space and can also be a safeguard from the backdrafting of toxic combustion by-products. The RETON 80 is a through-the-wall ventilator designed to provide a source of fresh air into a home or office. The unit can be installed in bedrooms, living rooms, or any other room in need of fresh air ventilation. The RETON 80 allows control over the volume and direction of air flow and is easy to clean. RETON ventilators are designed to work with mechanical exhaust ventilation or natural ventilation. Included washable filter. Easily fits wall thicknesses of 4&amp;quot; - 8&amp;quot;. Provides 10 - 20 CFM of fresh air infiltration.