This module is an adjustable step-down module. The output voltage can be changed by adjusting the blue adjustable resistor on the module. The input and output voltage difference is 1V, and the minimum voltage can be 0.8V.The IN- (input negative), IN+ (input positive), OUT- (output negative), and OUT+ (output positive) marked on the module must be connected correctly, otherwise the module may be .This linear module has constant voltage and constant current function (CC CV). and it has a good performance.When you use it as a charger. this module use good chip as core and it is stable. also its ripple is low to 50mV. Module parameters:Input voltage: 5V-32VOutput voltage: 0.8V-30VOutput current: adjustable maximum 5AConversion efficiency: 95% (the highest)Switching frequency: 300KHzOutput ripple: 50mV (max) 20M bandwidthLoad Regulation: 0.5%Voltage Regulation: 2.5%Operating Temperature: -40 to +85Rectification: non-synchronous rectificationModule Properties: non-isolated constant current and voltage module.Factory printing batch number is differentColour:RedMaterial:PCB+electronic components Package Contents:5 x CC CV Power Module Only the above package content, other products are not included.Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.