About this item LED Numeric Display: The buck converter features an LED voltmeter that provides accurate readings with only ±0.1V error. It operates with input voltages ranging from 4.0V to 40V and outputs between 1.25V and 37V. Note that if the input voltage drops below 4V, the voltmeter will not function and the display will turn off. To power it off, simply press and hold the switch for 1 to 4 seconds. You can easily turn it back on by tapping the switch quickly. Adjustable Buck Converter: This is a second-generation voltage regulator that runs at 150KHz. It is designed for energy efficiency and incorporates high-quality solid capacitors to maintain circuit stability and durability while filtering out high-frequency noise. Ease of Use: Adjusting the output voltage with this buck converter is straightforwardjust use a mini screwdriver. Terminal blocks are included, so soldering is not necessary unless preferred. Features & Safety: Two diodes on the input side protect the module again