Create waves of excitement for phase, beats, and frequency with a mesmerizing demo! Simultaneously release 9 pendulums to form a wave that dissipates before cycling back in phase to form the wave again. Each 2-line mount pendulum varies from slightly less to slightly more than 20 swings in 20 seconds. The rigid interlocking acrylic frame with installed offset tubing measures about 22" W x 19" H. Allow 40 min to assemble. Includes initiator stick and instructions.