The 2021 DUO is yet another MP4 player with dual audio jack outputs from Energy Sistem. Like the 4000 DUO, this one comes with two pairs of headphones, but it has less memory (4GB). Also, it includes a 1.5" display, integrated FM tuner/recorder, and Support for XviD, MP3, WMA, WAV, JPEG, and TXT formats.

The Energy Sistem 2021 DUO will retail for €54.90 and comes with a 3-year warranty.