Rockfon® Spanair® Torsion Spring Concealed Metal Panels install easily, using a grid-based suspension system, in an interior, exterior and seismic D, E, F application areas. Our Torsion Spring Plus panels are available in widths up to 4' and lengths up to 10'. These aluminum panels feature edge springs which allow the panels to nest in place and easily demount for simplified job site installation and routine maintenance accessibility.