The TDM2 is a very simple 433MHz band radio data modem. It provides a medium ranged half duplex, transparent data link between a pair of 9600 baud RS232 ports without any additional interface circuitry
VX2M is a 400MHz band ETSI Category 1 transceiver conforming to the Radiometrix TR2M pinout. It uses a sophisticated combination of techniques to produce a very robust device with excellent resistance to vibration