The 121SW-48 is a 48 in. baseboard supply air diffuser used for baseboard openings. This diffuser supplies conditioned air to your home and offers a subtle baseboard design. 1 simple pull of the latch and the single damper will close quietly and smoothly. Our product is constructed to ensure maximum airflow and compliment your home decor. Using our product to outfit your ventilation system will improve your home air circulation.. Air deflection: 3-way. Color: White. Color Family: Whites. Features: Louvered. Installation Location: Baseboard. Material: Steel. Maximum Duct Opening Length (in.): 45 in. Maximum Duct Opening Width (in.): 22 in. Pack Size: 1. Product Weight (lb.): 6.2 lb. Returnable: 90-Day. Shape: Trapezoid. Outside Length (in.): 48.0 in. Outside Width (in.): 2.5 in. Maximum Duct Opening Length (in.): 45 in. Maximum Duct Opening Width (in.): 22 in. Installation Location: Baseboard