Galaxy Audio RMCDU Rack Mount Tuner/CD and MP3 Player Combo The RM-CDU has FM/AM memory presets, Random, Repeat, Folder advance, Mute, and Program function. The RM-CDU will accept up to a 16GB USB, SD card/SDHC, and will play media from CD, CD-R, CD-RW, or MP3 disk, in either MPS or WMA format. The RM-CDU features easy to locate and read function buttons on the front panel.