I used the aurora wave lights as they r way cheaper than some other options (around $15) mine has color options but a cheaper version, Daren wave light, comes in just blue and is around $8 but keep in mind the area needs to b fairly dark. These units take batteries and shut off after 1 hour but it just takes a second to reset...Btw I had 2 and it covered my entire room, walls and ceiling...u just have to play with placement. The closer it is to the wall the less coverage u will get. Oh and the lighter color your walls are the brighter the effect (all my walls are dark but the wall the flag is on in a dark green)