Remote Control Track Section No. 6029 was used with O27 track and was produced from 1955 until 1963. Unlike its more readily found companion, the No. 6019, this section would only function to uncouple cars that used magnetic couplers.
This section replaced the No. 6009 in 1955. See the details that distinguish the differences in these two sections on the No. 6009 page.
Early issues of the No. 6029 came with a No. 90 Controller, while those issued later would be controlled by a No. 0190-25 Controller that was used with Lionel’s HO products. Two coiled wires connected the screw terminals on the bottom of the track section to the controller. The difference in the controllers that were used accounts for the two variations: