This products are tested to withstand harsh outdoor conditions (-17 F to 100 F), therefore are more than suitable for indoor use. You will need a fairly large space to do this product justice though.
When installing them in a room, please make sure you have enough space to bring out their full potential. Since they are designed to be used in the yard or on a house front, they will perform just as good in the garage and look really cool near a DJ set at a party, all year long.
For more info check out our Ultimate Guide to Laser Xmas Lights – http://laserchristmaslightshq.com/ultimate-guide-christmas-laser-lights/
Or our Holiday Projector Guide explaining the five highest quality and most affordable projectors on the market – http://laserchristmaslightshq.com/best-laser-light-projectors/