Will code plug into the receiver battery channel, battery (or any other unused channel connected to electric the tune power) insert the receiver lamp is not lit. The transmitter is set to a non runaway protection status (general throttle lever to the lowest it), press and hold the transmitter high frequency head lights and turn on the transmitter power LED lights shining in the the transmitter LED high frequency head, a few seconds, the receiver LED lights shining, shining stop frequency completed. The new receiver simply code the code after use to remove the plug on the code. Number of channels: 6 Modulation: for DSM2 Frequency: 2.4 GHz Size: 32 x 22 x 12mm Weight: 7.8g Voltage Range: 3.5v - 9.6v Antenna length: 30mm / each Colour:As Shown Material:plastic Package Contents: 1 x DSM2 RC Receiver Only the above package content, other are not included. Note: Light reflection and different displays may cause the color of the item in the a little different from the real . The measurement allowed is +/- 1-3cm.