The buzzer compatible with WiFi LoRa 32 V4 can be directly installed on its expansion board by selecting the B2B interface. This link only sells Buzzer!!! Specifications: Supply Voltage: 1~25V Supply Current: 5mA MAX (3V) Sound Pressure Level: MIN.65 dB, at 10cm at 3V Electrostatic Capacity: 12000±30% pF, at 100Hz 1V Oscillation Frequency: 4000 Hz Storage Temperature: -40~85℃ Color: Black Material: PCB Specification: 1 piece Package Contents: 1 * Buzzer Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.