Main Parts : 
Power Jack x 1
ATMega328p x 1
16MHz Oscillator x 1
2x2-pin Stackable Header x 1
1x10-pin Stackable Header x 1
2x3-pin Stackable Header x 1 (ICSP)
Serial Interface : UART
Input/Output Format : MIDI
SW1~SW4 : MIDI Channel Selection
VR1~VR4 : Synthetic effect adjustment
Brick Unit : 4 x 5

Note : You may use ICSP interface to update firmware