This video shows a pair of the Railking 5-wire gates in operation. Nice slow action, fairly realistic, though a pain to wire. And noisy! These are activated by a set of two Z-1011 trackside sensors, and one Z-1050 block signal, all activating a Z-1008 relay. I had to get Dennis Zander to give me some help with a couple of blocker diodes in the wiring so the sensors would play well together.
Definitely a 3 wire device would be a whole lot easier to install.