Voltage Adjustable Power SupplyDC 3~12V adjustable, Max 3A (3000mA) 36W. You can get any voltage between 3~12V by turning the knob, such as 3V 4.5V 5V 6V 7.5V 9V 12V. It can supply with any amp under 3A, such as 1A, 1.5A, 1.8A, 2A, 2.5A, 3A. 14pcs Frequently Used Tips It comes with an original 5.5x2.5mm tip and 14pcs interchangeable tips: 6.5x4.4mm+Pin, 5.5x2.1mm, 5.5x3.0mm+Pin, 5.0x2.5mm, 6.3x3.0mm, 5.5x1.7mm, 4.8x1.7mm, 4.0x1.7mm, 3.5x1.35mm, 3.0x1.1mm, 2.5x0.7mm, Micro-USB, Type-C and DC terminal connector. Come with Polarity Converter The original tip is inner positive(+), outer negative(-). We especially add a reverse polarity converter for devices with inner negative polarity (-). LCD display will show the output voltage, in case that wrong voltage regulation damage your device. 5-Point Safety FeaturesBuilt-in automatic over-voltage cut-off, over-current cut-off, over-temperature cut-off, short-circuit cut-off, anti EMI protection. Certified by FCC, CE, ROHS