This versatile piezo-element module can be used for both input or output! It can be used as a noise-maker driven by your microcontroller for audible feedback of events, and it can also be used as a knock-detector input to sense events and react to them. Includes a built-in 1M resistor to allow the piezo element to detect shocks.

• Frequency response 0-20KHz, peak resonant frequency: 4KHz +/-500Hz
• Sound pressure level at 10cm: 75dB (min)
• 1 to 25V rated voltage (3 to 5V typical)
• Built-in 1M resistor for knock sensor functionality
• Dimensions: 23(W) x 16(H) x 5(D)mm