Main Parts : 
Power Jack x 2
IC RTS0072B x 1
MIC x 1
Variable Resistor x 1
Audio Jack x 1
2x2-pin Stackable Header x 1
1x7-pin Stackable Header x 1
Input : Line in or Mic
Sound Effects : 
- SEL : Audio frequency selection
- NRL : Audio volume amplification
- ROB : Robot sound
Brick Unit：6 x 5

Note : Use S1, S2 port to shift the input audio (1Khz) to 660Hz, 800Hz, 1333Hz and 2KHz. Use VR to fine tune the frequency