NEW: Traxxas TSM TQi 2.4GHz 5-Ch Receiver 6533 - *X-Maxx / XRT Edition* - These receivers come factory programmed for the X-Maxx / XRT profile and won't operate properly without a temperature sensor plugged in.  To use them without a temperature sensor you need to reprogram them using the bluetooth/app.   It can be done but please look into this process if you are purchasing the receiver for a different model or use it without the temp sensor.