Add a little life and light to your structures with this starter set! Simply glue a light box behind a window, install an LED, and turn on only the light in that ′room.′ Boxes are made of heavy plastic to prevent light from shining through. Set includes three each of four boxes for windows measuring about 11/16 x 1′ (18 x 26mm), 3/8 x 13/16 (16 x 21mm) 1/2 x 3/4′ (12 x 19mm) and 1/2 x 13/16′ (14 x 22.5mm). Kit includes one white LED additional LEDs are available separately in sets #769-6007 (yellow, pack of 10) and 6008 (white, pack 10), or use Building Interior Lighting LEDs #769-6017 (yellow) and 6018 (white), all sold separately.