ZGM - Zero Glitch Module is an opto isolator for use in any electric RC model.
It is designed to cut all electrical connection between the speed control and the receiver whilst still maintaining a strong signal connection. This removes any interference caused by the connection between the speed control and receiver and has been known to improve the strength of the connection and also increase the range of your model.
LEDs are used to show correct connection.
The ZGM is also 100% waterproof so can be mounted anywhere in the model.
As the Opto-coupler is an electrical barrier, your receiver must have its own power supply, the Opto-coupler will not pass BEC power back from the speed controller to the receiver.