The 2004 Series is a 2 x 2 ft T-BAR 3 Cone Step Down Diffuser. The "cone" shape of the diffuser allows for a maximum volume of airflow into the air-conditioned space. TRUaire™ Step-Down Supply Diffuser, 3-Cone, Series: 2004, 24 x 24 in, Square Diffuser Shape, 23-3/4 in Width, 4-3/4 in D, 23-3/4 in Height, 4-Way Diffusion Pattern, Pristine White, 24 ga Steel, Powder Coated, Import