Dear customer: Thank you for choosing my store for shopping. The following are the matters needing attention for shopping:A. Economic transportation: detailed tracking information will not be included. Most of the packages will cause delayed delivery within the expected delivery time, so you need to be patientB. Each product link: There will be different option variants. If you do nt know how to select the product you want, please contact me, I will be honored to solve this problem for you.C. When you receive the package, there is product damage / product problem / error product and shipping problem, please contact me in time, I will solve it for you!D. If you are a wholesaler / distributor, a large number of orders and quantities, to provide you with factory prices, and hope to be honored to reach a partner with you!GOOGZON store: I wish you a happy life! 300W20A black PCB and blue PCB, randomly sent! Same function! Different base plate colors do not affect the use! Features: With a wide input voltage range from 6V to 40V, the step-down converter can accurately adjust output voltage and current. The efficiency can be up to 96%, measured at 20A, converting 24V to 12V. It is designed with 75V/80A large current dual MOS tube. Input and output use high frequency low resistance electrolytic capacitor, low ripple, stable output. Wiring is convenient with these large current 30A screw terminals. The buck module has 2 heat sink that could enhance heat dissipation. When there is a big difference between input and output voltage, please decrease power and current. Specifications: Input Voltage: 6V to 40V DC(10V to 40V is suggested) Output Voltage: 1.2V to 36V DC Output Current: 20A(max.), 15A(suggested) Efficiency: 95%(24V to 12V, 20A) Output Ripple: 50mV Wiring Method: Terminal Short Circuit Protection: Self-recovery(cannot short circuit for long time) Size: 60 x 53 x 27mm / 2.36 x 2.08 x 1.06" VO+: Output positiveVO-: Output negative+IN: Input positive -IN: Input negativeCV: Output voltage adjustmentCC: Output current adjustmentEN: Enable, low voltage level shut off output; suspension, high voltage level is effectiveWhen input and output is common grounded, no-load CV output constant voltage,CC output constant current