Motorola RDX Series software can be found by visiting the Motorola Solutions website, finding the RDX Series and clicking on the resources tab. The RDX Series software tab can be found midway down the left side of the page.
The Motorola RKN4155 will program the following Motorola two way radios:
RDU2020, RDV2020, RDU2080D, RDV2080D, RDM2020, RDM2080D, RDU4100, RDU4160D, RDV5100, CP110