MAPRO make improvised version of conventional multicone square diffuser with only one passage of all four sides with larger area by stepping down the core. Rest of all the cores is blocked with the sheet fixed to the core ring forming the removable plaque.
The appearance of panel or plaque shall have aerodynamic rigid, hemmed edges around the perimeter and shall be the single piece construction the panel shall be flat, smooth and shall be free from any welding and forming blemishes.