This small piezoelectric modules can collect energy and solar energy. Where there is a bridge, it is possible to enter into a piezoelectric elements (PZ1 and PZ2), can be directly input (VIN) into DC source. Current two bridges are less than 20 volts. In addition, this board can be used alone as a buck regulator. Generally speaking, when the LTC3588 enters a sleep state, the quiescent current input and output is very small. The buck regulator is automatically enabled to their normal operation. Four kinds of access interfaces to selectively output voltage (1.8V, 2.5V, 3.3V and 3.6V), the output current is constant current of 100mA. 2.7V to 20V Input Operating Range Integrated Low-Loss Full-Wave Bridge Rectifier Up to 100mA of Output Current Selectable Output Voltages of 1.8V, 2.5V, 3.3V, 3.6V High Efficiency Integrated Hysteretic Buck DC/DC Input Protective Shunt - Up to 25mA Pull-Down at VIN equal 20V Wide Input Undervoltage Lockout (UVLO) Range Colour:Red Material:PC+Metal Size:. 20x12x3mm/0.79x0.47x0.12inch Package Contents: 1 * energy module 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.