Features Automatic MPPT detection: When the AUTO MPPT test button is pressed, the instrument automatically adjusts the test interval according to the current power value and refreshes the digital display. For example, when the power of the solar panel is 100W, it is refreshed every 5S, and when the power is 300W, it is refreshed every 15S. Manual MPPT detection: When the manual MPPT test button is pressed, the instrument starts to scan the maximum power point and refresh the digital display. Open circuit voltage detection: When the VOC test button is pressed, the voltage of the solar panel will be displayed in real time. Multiple protections: over-voltage protection, over-temperature protection, over-current protection, over-rated power protection. Power supply mode: photovoltaic panel power supply, no need for additional power supply, easy to use. LED digital tube display (WS400A)/LCD liquid crystal display (EL400B), easy to use and read. Specification: Material: ABS Model: WS400A/EL400B (optional) Power: 0.1-400W Voltage: 12-60V Current: 0-20A Display mode: LED digital tube display (WS400A)/LCD liquid crystal display (EL400B) Backlight: None (WS400A)/Yes (EL400B) Power supply mode: photovoltaic panel power supply Item size: 165*80*30mm/6.5*3.1*1.2in Packing size: 250*130*65mm/9.8*5.1*2.6in Package weight: 500g Note: Due to the different monitor and light effect, the actual color of the item might be slightly different from the color showed on the pictures. Thank you! Please allow 1-m measuring deviation due to manual measurement. Packing list: 1 x Multimeter 1 x MC-4 connection line 1 x Alligator clip cable 1 x Manual 1 x EVA toolkit Package List