The FlySky FGr4D is a four-channel, two-way 2.4GHz receiver using the AFHDS3 (Third Generation Automatic Frequency Hopping Digital System) protocol. It features dual antennas, a PPX6 nano waterproof rating, and a compact, lightweight design. Four Newport function interfaces can be customized for various signal types including i-BUS2, S.BUS, i-BUS, and PPM, and the FGr4D can also function as a PWM converter — making it ideal for model cars and boats.