LM2596 Adjustable DC-DC Buck Converter Module with Digital Voltmeter, Calibratable Version, 4–40V Input, 1.25–37V Output, 3A Max, Pack of 2

["Built-in Digital Voltmeter with High Accuracy Integrated LED voltmeter displays input or output voltage with ±0.1V accuracy, measurement range 0–40V. (Note: Voltmeter does not operate when input voltage is below 4V.)","One-Button Voltage Switching & Memory Function Single tactile button allows quick switching between input and output voltage measurement, with LED indicators showing the active channel. Settings are saved automatically and retained after power-off.","Voltmeter On/Off & Calibration Support Long-press the button (1–4 seconds) to turn off the voltmeter. Advanced calibration mode allows fine adjustment of voltage display accuracy (reference range 2.45–2.60V), with values stored permanently in onboard memory.","Wide Input/Output Range & Stable Performance Input voltage range: 4.0–40V (input must be at least 1V higher than output). Adjustable output voltage: 1.25–37V continuously. Supports up to 3A peak current, with 2A recommended for stable operation.","Easy Wiring with Screw Terminals Equipped with screw terminals for quick, solder-free installation, while retaining solder pads for permanent connections. Ideal for prototyping, DIY electronics, power supply projects, and embedded systems."]