Features: With transparent acrylic shell, easy to read while protecting the module Using LCD display screen, Voltage and Current can be displayed simultaneously Using button adjustable voltage, left button to reduce the voltage, the right button to increasing voltage. press button one time can adjust 0.04V voltage, press and hold more than 1 second to quickly adjust voltage. Can withstand 100,000 presses; Compared with similar potentiometer voltage regulation more convenient and fast. Only can be used as a step down converter, and input voltage should be >1V higher than output. Specifications: Input Voltage: DC 8V~60V (Recommended within 55V, Input voltage must be higher than the output voltage 1V above) Output Voltage: DC 3V~32V Continuously adjustable (It can save the last set voltage automatically) Output Current: Maximum 7A (Recommended use within 5A, Please pay attention to heat dissipation.) Accuracy: 1%, the voltage three bits display, the current two bits display, the unit is "A". Input Anti-reverse Protection: Yes Short Circuit Protection: Yes Conversion Efficiency: Maximum up to 95% Load Regulation S(I): ≤0.8% Voltage Regulation S(U): ≤0.8% Size: 62 x 44 x 18mm / 2.59 x 1.73 x 0.7in Weight: 67g Voltage Calibration Method: Power-off no load status, press and hold the left button access the power supply, release the left button, the display voltage starts flashing, then using multimeter measured the output terminal voltage, press the left and right keys to adjust the module display voltage value is the same as the multimeter display voltage value, for example: multimeter measurement is 12.6V, then the module can be transferred to display 12.6V, three seconds automatically save, re-power that voltage calibration is complete. The error can be calibrated within 0.04V, if the error is greater, you can try to calibrate again. Current Calibration Method: After calibrated the voltage is completed, connect the load, with a multimeter to measure the actual current value, power off the power supply, then press and hold the right button access the power supply, release the right button, the display current value starts to flash, press the left and right keys to adjust the module display current value is the same as the multimeter display current value, such as: multimeter measurement is 1.8A, then the module can be transferred to display 1.8A, three seconds automatically save, re-power that current calibration is complete. Package includes: 1 x Step-Down Module Kit 1 x Acrylic shell Note: If it is used for charging, after charging, please first disconnect the battery end and then the input end to prevent the battery from damaging the module by backflow. Or at the output end add a diode preventing backflow .