I'm in the process of upgrading one of my electric boats and was advised to go for a Hitec HFX S/JR speed controller.

In the past I've only used bog standard esc's.

Looking at the instruction leaflet there is one bit of wiring I do not understand having not come across this in my short time of radio control.

Coming from the ESC is an orange lead marked to FET Servo power.

What do I connect this to, and do I have to connect it


thanks