Rhythm Joyful Moment musical wall clock uses a faceted frame with colored LED lights that flash and Sync to one of 18 melodies that play on the hour. A rotating wheel that holds four enchanting Swarovski crystals, while the two sets of bells rock in a perpetual motion. Clock is battery operated. A demo button is located at the bottom of the clock and has a light sensor so the clock may turn off in a low light, night-time environment. There is also a volume control and an on-off switch for for the music. Two “D” sized Batteries are included.