The expansion board comes with 6 fool-proof 3-Pin sockets, compatible with hundreds of DFRobot’s Boson and Gravity modularized electronic blocks, covering most popular digital and analog sensors and actuators, supporting sound, light and motion interaction.
Click the link to learn more about DFRobot’s Boson module: https://www.dfrobot.com/boson 

Click the link to learn more about DFRobot’s Gravity module: https://www.dfrobot.com/gravity 

Moreover, the on-board 3.5MM headphone jack and volume knob supports direct connection of headphone.
To ensure a steady current supply for these peripherals, the expansion board can be powered externally through the USB power port.