Constructed to help evenly spread out airflow from your duct opening, the 801 series butterfly air damper with installation ring is used to cover duct openings in conjunction with a round air diffuser. The design is simple and features high quality steel, brown powder coat finish removable knob control and a plastic key to open and close the damper. Using our product to outfit your ventilation system will improve your home or office air circulation.. Air deflection: Round. Color: Powder Coat Brown. Color Family: Browns/Tans. Features: No Additional Features. Installation Location: Ceiling. Material: Steel. Maximum Duct Opening Length (in.): 6 in. Maximum Duct Opening Width (in.): 6 in. Pack Size: 1. Product Weight (lb.): 1 lb. Returnable: 90-Day. Shape: Round. Outside Length (in.): 7.5 in. Outside Width (in.): 7.5 in. Maximum Duct Opening Width (in.): 6 in. Maximum Duct Opening Length (in.): 6 in. Installation Location: Ceiling. Outside Width (in.): 7.5 in. Shape: Round