Features: Operating voltage:DC 4.5 ~ 30V Measure voltage: DC 0 ~ 100V Minimum resolution(V): 0.1V Measure current :DC 50A (require external shunt) Minimum resolution(A): 0.1A Operating Current: !#!lt!*!20mA Display: three 0.28" LED digital tube Display color: Red (dual display) Dimensions: 48 x 29 x 21mm Mounting cutout: 45.5 x 26.5mm Refresh rate: about 500mS / times Measure accuracy: 1% ( 1 digit) Operating temperature: -10 to 65 Operating Humidity: 10 to 80% (non-condensing) Working pressure: 80 to 106 kPa Wiring: Black line (thin): vacant or buck circuit (module) negative Red line (thin): power supply+ Black line (thick): COM common measuring Red line (thick): PW+ measuring terminal voltage input positive Yellow line (thick): IN+ current input+ (Please refer to the wiring diagrams for more details) Notice: The voltage between the thin red and thin black lines must be within DC 4.5-30V The ammeter can only be connected to the negative of the device under test Exceeds 5A long-term full load working continuously it is recommended that the measurement side of the leads are directly soldered to the socket When the black thin line vacant it is better to use insulating tape around the exposed part of the wire to prevent short circuits If just be used as a voltmeter it is recommended that the yellow line and the black line were connected together to prevent the ammeter digital flashing Package include: 1x Digital Volt Ampere Meter