Octopus Electronic Bricks, you can use them to build electronics projects just as easy as piling bricks. By using Octopus electronic bricks, you may connect Arduino/Freaduino compatible boards easily with various digital, analog, and I2C/Uart interfaces. These breadboard-less firm connections are prepared to extensive modules like potentiometers, sensors, relays, servos even buttons, just plug and play.

Octopus Passive buzzer Brick is based on a passive buzzer, it could control the volume by PWM. The distinction is active buzzer stickers.

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ELECFREAKS Passive Buzzer Brick