The FrSky Servo Channel Changer is a tool designed for setting the channel of FrSky S.BUS & CCPM compatible servos (e.g. D12MB, Futaba S.BUS servos and the FrSky S.BUS to PWM Decoder).
Simply connect the servo or decoder to the servo connection port of this device and a power source to the battery connection port.
Then use the roller switch to change and set the channel numbers accordingly.