Check the listing for details. Rotary Rotating Anniversary Clock Pendulum Drive Movement Battery Power. Condition: New. Listed at 12.10 USD. This is a NEW battery powered pendulum only movement for a modern anniversary clock. This is used in many of the newer anniversary clocks to make the ball pendulum spin back and forth. Powered by a single AA battery (not included). Comes with 4 ball pendulum as shown in the photograph. The movement measures 2 9/32" x 2 9/32" x 11/16" thick. The overall length shaft is about 11/16" long. The threaded post in the center is about 1/4" diameter and 5/16" long. 4 ball pendulum measures 2 5/16" tall and 1 11/16" wide. About 3 3/8" tall when assembled. 1 year manufacturer's warranty. Thanks for looking! The shaft is in the center of this unit. PLEASE NOTE!!! THIS MOVEMENT IS ONLY FOR MAKING THE PENDULUM SPIN BACK AND FORTH IN AN ANNIVERSARY CLOCK, IT IS NOT A TIMEKEEPING MOVEMENT.