It is very interesting audio project. It is convert our human voice into robot voice. That means it is a ROBOT Voice Changer. We familiar with voice changer application in mobile phones. This is a hardware version of that type of applications. It contain an onboard microphone and an AUX input. So it can capable of changing voice from microphone and AUX input. So by this AUX input we can change our favorite music to a robot music. The microphone input convert it to robot voice in real-time. It contain a good quality speaker. It is capable of producing loud voices. It contain volume and pitch control presets for selecting our custom modes. The whole circuit is works from 9V battery. So it is easy to operate. It is very good for students and hobbyists. The PCB is very high quality and FULLY ASSEMBLED. The circuit is designed and tested by Engineers. NOTE: No battery included.