Brand Jtron Model 03100412 Quantity 1 Color Black Material Plastic Specification Operating voltage: DC 4.5~30V; Measure voltage: DC 0~100V; Minimum resolution(V): 0.1V; Measure current: 100A (Shunt resistor needed (100A/75mV)); Minimum resolution(A): 0.01A; Operating current: <20mA; Display: 0.28" LED 3-digital tube; Display color: Red and Blue (two-color 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: -10C~65C; Operating Humidity: 10%~80% (non-condensing); Working pressure: 80~106 kPa Features 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; 10A below ammeter (include 10A) built-in shunt does not require external shunt; 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 Application DIY projects; Suitable for automotive / electric cars / motorcycles battery monitoring or other products voltage current measurement English Manual/Spec Yes Other Dual LED: Red voltage Blue current Display Voltage Current at same time; This panel meter is common ground design it means that the (measure ground wire) and (power supply ground) is common ground. Power Supply DC 4.5~30V. With reverse polarity protection but the max power supply can not exceed DC 30V. Wire Connection please check the description pictures. Power supply (two line socket): Red wire: Power Supply +; Black wire: Power Supply -; The power supply voltage can not exceed 30V; Measure Port (three line socket); COM: Black wire measure common ground; PW+: Red wire Measure Voltage + IN+ Yellow wire Measure current input. if use the voltmeter function only please connect the Yellow wire and black wire together to avoid the Interference Packing List 1 x Digital volt ampere meter (12cm-cable)