Universal lead servo reverser for 4.8-6.0 Volts. Plug the servo reverser into the receiver, plug the servo being used into socket lead from the reverser. Ensure the servo connections match the pos. (+), neg. (-) and signal markings on the reverser label. Switch the radio system on, yuo will find one of the servos is now reversed, and may find that this servo's neutral point has changed, use a small screwdriver to adjust the variable resistor on the printed circuit board to correct this. (take care to ensure that the adjuster is not forced beyond its end point).