For traditional style ceiling air diffusers. Divert cold or hot air from HVAC air conditioning units from blowing down directly. Easily installed underneath a standard 2’x2′ HVAC diffuser. 24″ wide x 12″ long x 2.75″ high. .080 gauge polystyrene construction. NOTE: Air Diverters are intended to be used one at a time. Do not block the entire diffuser by using two side by side.