4pcs DC~DC Step Down CV Adjustable Current Voltage Power Supply Module 3~40V to 1.5~35V Features: DC-DC step down converter module convert  3V~40V to 1.5V~35V, max current is 3A. Buck converter module is used for voltage step-down so please make sure that input voltage is 1.5V higher at least than output voltage. The buck module can be quite efficient, making it useful for voltage step-down. Convenient e, easy to wire, there are total 4 pieces of modules in one set. Widely used for low voltage system power supply, 6V, 12V, 14V, 24V battery charging and regulated power supply. Specifications: Input Voltage Range: DC 3V~40V Output Voltage Range: 1.5V~35V (adjustable) Maximum Output Current: 3A Size: 4.5*2.2cm/1.8*0.9in Quantity: 4pcs Weight: 11g(approx.) Note: Input voltage should be at least 1.5V higher than output voltage. Package Includes: 4 x Step Down Modules