niceeshop(TM) LM2596 DC-DC Buck Converter Step Down Module Power Supply Output 1.23V-30V Dimensions: 6.5x4.8x1.5cm/approx 2.6x1.9x0.6inches Input:DC 3V to 40V; Output:DC 15V to 35V Voltage continuously adjustable,high-efficiency maximum output current of 3A The 36u thickening circuit boards,high-Q inductance with output value of high-power LED indicator