Brass finish Bobs are included free with the purchase of all Pendulum Movements, choose the size that best fits your clock design. The length of the Pendulum Rod adjusts down from 16" in 1" increments and has scored breakaway lines. This pendulum bob has a diameter of 3 1/2". Bobs can also be purchased separately for $3.95, however, they are made for the movements listed on this website and may not fit other movements.