The cable length of the D9M is 3 m. (No other lengths are available.) It can be extended, but the maximum length is 100 m. (There are two lead wires per cable so the total maximum length of the lead wires is 200 m.)

There are no specific requirements for the extension cable, but it is recommended that you use the same type of cable as the one that is attached to the D9M (0.75 mm2) or thicker.