X2 Pro Transponder (Standard) The Pro Transponder operates in X2 mode, 2way communication is available and timing resolution can be up to 0,0001 seconds. The transponder can be connected to the CAN bus of the internal electronics. This way it is possible to send and receive messages to the race electronics. The transponder is equipped with one G sensors with a X, Y, Z indication. Direct Power only. The X2 Pro Transponder Plus The X2 Pro Transponder Plus has the same specifications as the X2 Pro Transponder and additionaly has a backup battery, a backup TranX Transponder and a second G sensor. The back-up battery which when fully charged will give 200 minutes of backup power when the transponder is operating in X2 mode. A backup TranX transponder can be activated in case of emergency when running on the internal backup battery in order to extend operating time.