This voltage regulator can be used to step down 12 Volts to any voltage by twisting the screw in the blue box. It is used to step down the 12 Volts from the battery to Volts for the 3D printed Servo Valves.
Pressing the IN and OUT buttons allows the regulator to display the voltage coming in and out.
HiLetgo 2pcs LM2596 Adjustable DC-DC Step Down Buck Power Convert Module 4.0-40V Input to 1.25-37V Output with LED Voltmeter Display
From https://www.amazon.com/dp/B00LSEBYHU?psc=1&ref=ppx_yo2_dt_b_product_details