Ohuhu174; Solar String Lights/Fairy Lights for Christmas Tree, Bedroom, Garden, Wedding, Party - 21 Ft, 50 LED, Multi-Color Powered by solar energy, no power wire needed. Can continuously work more than 8 hours at night if the panel absorbs enough sunshine during sunny day. Waterproof - suitable for both indoor and outdoor use. Comes with power ON/OFF button and mode switch button [Constant and Flashing] at the back of the solar panel. Ideal decorations for Christmas or other celebration occasions, such as wedding, party, Valentine's day, etc.