Youmile 6PACK Step-Down Power Supply Module LM2596 LM2596S Buck Converter DC to DC 3.0-40V to 1.5-35V High Efficiency Voltage Regulator Module by Amazon.co.uk

• Input: DC 3 V to 40 V (input voltage must be 1.5 V higher than the output voltage, no boost)

• Output: DC 1.5 V to 35 V voltage is continuously adjustable, maximum output current is 3 A

• Features: all use high quality solid-state capacitors, 36 u thickening circuit boards, high-Q inductance with LED indicator output

• Quantity: 6 pieces; Size: 43 x 21 x 14mm/1.7 x 0.8 x 0.6inch (with potentiometer)

• Steps: connect to power source, adjust the swirl button on the blue potentiometer and monitor voltage with multimeter to get the needed voltage (The factory have tested these at max voltage so they are very high by default, takes about 15-20 turns CCW before the voltage starts ramping down)