Brodak.com sells the 3-line systems (handle and bellcrank are matched) but I have since changed over to the electronic control systems. Basically I have 2 lines, both insulated and then mount one or more servos in the model. The elevator is controlled by a typical stunt bellcrank and I fly with a stunt handle. But the flying lines are nylon coated salt water fishing leader that transmit a signal and ground down the two insulated lines. If the lines are not insulated system does not work.

You can use a servo driver for one function such as throttle or use the JR radio with DSC function to control the system. You can install a JR radio into a CL model, pull the crystals and hook up the system using the DSC system (direct servo conection) with the signal going down the insulated lines.

Most scale folks use the electronics, but due to line drag the insulated lines are not pratical for precision aerobatics. Carrier folks tend to use the 3-line systems even though the 2-line systems are legal for carrier.