This is a set of 400 LED Lights that are fitted to a battery operated timer box. The box requires 3 x AAA Batteries that are not included. The timer unit is safe to use indoors or outside. The multi-coloured LED bulbs are able to be set to turn off and on after a set time with ease and they can also be set to run in any one of the set of 8 mode sequences pre-programmed into the unit so you can choose your favourite pattern. A fantastic xmas decoration that will look great in your home or office.