Woodland Scenics JP5716 Just Plug(TM) Lighting System, Light Block Kit

No electrical knowledge or special tools needed, just plug and you're done! The Just Plug(TM) Lighting System is a quick and easy way to add realism and interest to new and existing layouts and other projects. Individual bulb brightness can be controlled, and the modular design allows for easy expansion. Just Plug is compatible with DCC and works for any scale
Blacks out individual windows
Eliminates light leaks and secures building to layout
Seals building seams
Prevents glowing walls