Bell 11791 Arial Plus Multi Backlit High Output UGR<19 LED Panel - 25mm 1200x600mm, White, 4000K, Emergency 3600-6750lm. The Arial Plus Multi is our leading wattage switchable panel. With a high lumen output of up to 125 lumens per watt, this panel is ideal for areas that require high lux levels. The Arial Plus Multi can be installed in areas where TPa rated lighting products are essential, such as emergency exit routes including stairways and corridors.