A simple telescopic system works using a pickup bush on the top of the door. This is used as the first door moves over, hits the pickup bus, and causes both doors to move together. This system can be seen in products such as the GEZE Rollan Telescopic Sliding Door Kit. However, the simple system is not as smooth as the progressive system and does not have a belt drive. But the simple system is much cheaper and allows for one door to be open while the other is fully closed.
