5 Vdc

1×Button for Arduino reset
1×LED for power status when 5 Vdc is applied to the shield
1×LED for busy status when the shield is playing MP3 files
1×Button for play/pause
1×Button for prev/vol-
1×Button for next/vol+

1×Pin headers in Arduino shield form factor
1×3.5 mm stereo audio jack for earphone
1×Pads in 1×4 form factor for connecting to L+/L-/R+/R- of a maximum 3 W rated external stereo speaker
1×Pads in 1×3 form factor for expanding ADKEY which carries out additional MP3 functions
1×microSD card slot for connecting to maximum 32 GB microSD card
1×USB type A socket for connecting to maximum 32 GB thumb drive
1×USB type Micro B socket for connecting the shield with PC
6×Male pin header in 1×2 form factor for selecting UART TX pin
6×Male pin header in 1×2 form factor for selecting UART RX pin

69 mm×53 mm