This article is used to transmit the movement back and forth to the dildo. One end is inserted and secured by a strong permanent magnet in the LM42P. The Holder of the dildo is clipped on the other end of the Rod. The Vac U Lock Adapter can be screwed on it. One of this arm is already included in the LM42P. If you want to use the LM42P for two, you will need to order an extra Rod.