The clock's face splits and rotates while music plays to one of 40 songs on the hour, every hour 22 Preciosa Crystals add impressive detail and charm; 22 brilliant crystal-enhanced pendulum spins Plays classic songs, glass bell tracks or holiday favorites; Sensor disables lights and music when it is dark Volume control allows you to select just the right sound level; Battery operated (batteries included) Dimensions 17 1/2 x 16 x 3 3/4 inches