When both are struck at the same time, an acoustical phenomenon known as "beating" is produced. A gentle tap of the mallet and the Zenergy Meditation Chime emits a powerful tone that lasts and lasts. The rods will seem to ring with the same pitch, but you will notice a distinct pulsation or rhythm - in this case approximately 12 beats per second. Relax, refocus, and rejuvenate with these good vibrations. Comes with wooden mallet and listening exercises. Cherry finished hardwood with 2 silver polished aluminum rods. Measures 7 1/2" long, 3" wise and 1 1/2" tall.