The light boxes provide completely new clear lighting of each single room. For lighting we recommend our item no. 6007, 6008 and 6017/6018. Lightboxes should be fixed inside the house behind the windows. Light shining through is prevented. Dimensions light box (maximun window size) : 18 x 26 mm, 16 x 21 mm, 12 x 19 mm, 14 x 22,5 mm .