Etronix Futaba RX Charging Cable ET0273 4mm Banana Bullet Plugs 16cm lead wire

The primary difference between Futaba and JR servo connectors lies in their keying/polarity and housing design. Futaba connectors have a prominent tab on the signal (usually black) wire side of the female connector to ensure correct polarity, while JR connectors typically have beveled corners on the male connector and angled tabs on the female connector to help with alignment. Futaba plugs can often be modified to fit JR connectors, but JR plugs may not fit Futaba receivers without modification.

Futaba and JR connectors are generally compatible due to their similar pin spacing and overall size, though Futaba connectors have a keying mechanism that might require modification to fit into a JR connector housing.