This 6 inch servo extension has "S" type (also called JR) male and female connectors. Most of the servos that we sell come with the male "S" type connector, so they work fine with this extension.
If you wish to plug in a servo with a Futaba "J" type male connector, you can simply shave off the little plastic ridge on the side of the "J" connector, and it will fit in the female connector on this extension.
This servo extension will plug into most receivers, including Futaba, JR, Spektrum, GWS, Cirrus, Blue Bird, Blue Arrow, Corona, Berg and Hitec.
The wire colors are: Red = battery positive Brown = battery negative Orange = signal.