1PCS DC-DC Step Down Module LM2596 3-30V to 1.2-18V Adjustable Power Supply Converter Input: DC 3V to 30V (input voltage must be higher than the output voltage to 1.5v or more. Can not boost) Output: DC 1.2V to 18V adjustable voltage, high efficiency, maximum output current of 3A. Features: 36u thick circuit boards, high-power high-Q inductors Size: 37mmx37mmx14mm Conversion efficiency: 93%(highest)