Features: Our product output is constant current and Voltages, with true double loopings protections that simultaneously protects Voltages and current. Our product have two potentiometers that can adjust Voltages and current, and can be set to the appropriate Voltages and current size. If the Voltages and current are too highs, it is easy to damage electronic components during testing, causing permanent damage. The output Voltages is DC110~2600V. You can turn the Voltages adjustment button clockwise to increase the Voltages, and turn it counterclockwise to decrease the Voltages. The output current is 0.25~3.4mAh, you can turn the Voltages adjustment button clockwise to make current larger, and turn it counterclockwise to make current smaller. When testing MOS tubes, transistors and Diodes, recommend to adjust current to a minimum scale of 0.25mA. When testing LED backlights panel, recommend to adjust current to the maximums scale of 3.4mAh. Specifications: Material:ABS Output Voltages: 120-2700VDC (constant Voltages and current) Output current: 0 2-3.8mA (constant Voltages and current) Lithiums battery capacity: 3 7V 600mAH Charging interface: USB C Charging current: 500mA Charging time: 70minutes Light Color:Redness,Blue Note: Please allow 1mm errors due to manual measurement. Due to the differences between different monitors, the picture may not reflect the actual color. Package includes: 1Set Transistors Tester