Input methods: IN + input is level, IN-input negative.
Output way: OUT + output is level, OUT-output negative.
Adjustment: first correct by input power supply (3-34 V, between) again using a multimeter to monitoring output voltage and the potentiometer (turn step-down, in reverse chronological turn boost).
Output voltage: 4-35 V continuous adjustable (the construction no-load commissioning) our default shipping voltage 12 V if you require other voltage can tune ourselves.