Compatible with ODROID-C5 / ODROID-C4, this is a Audio amplifier board with on-board sound PAM8406 amplifier.
It can be used by plugging directly into the 8-pin of the 40-pin header connector and 2-pin Audio DAC line-out header connector of ODROID-C5 / ODROID-C4.

• Volume control to out of speaker and headphone simultaneously.
• Display 0.91 inch 128 x 32 pixels OLED board via I2C.

Wiki Link: https://wiki.odroid.com/accessory/add-on_boards/audio_amplifier_board