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. 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. Photovoltaic panel power supply mode, no need for additional power supply, easy to use. Service: If you have any questions about the product, please contact us via email in time. Professional customer service will reply to you within 24 hours. 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 1-3mm 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