Dear customer: Thank you for choosing my store for shopping. The following are the matters needing attention for shopping: A. Economic transportation: detailed tracking information will not be included. Most of the packages will cause delayed delivery within the expected delivery time, so you need to be patient B. Each product link: There will be different option variants. If you do nt know how to select the product you want, please contact me, I will be honored to solve this problem for you. C. When you receive the package, there is product damage / product problem / error product and shipping problem, please contact me in time, I will solve it for you D. If you are a r / distributor, a large number of orders and quantities, to provide you with factory prices, and hope to be honored to reach a partner with you GOOGZON store: I wish you a happy life Old version The factory has adjusted the internal interval of the PCB. If you have a back PCB board, please dont buy it. Working voltage of Meter itself:DC 4 - 30V(The maximum input voltage can not exceed 30V. Otherwise the meter will be burned) Working current of Meter itself:20mA Voltage Measuring range: DC 0 - 100V Current Measuring range: DC 0 - 10A Voltage resolution (V): 0.1V Current resolution (A): 0.01A Measure accuracy: 1% ( 1 digit) Display: 0.28" digital tube Refresh rate: about 300mS / times Dimensions:48mm*29mm*26mm Operation Temp: -10-+65 New version Real-time power is displayed alternately with current, no setting required. To measure temperature, connect NTC sensor, Working voltage: DC4~30V Voltage range: DC0V~100V (0.02V jump) Voltage error: 1V Current range: 10A (0.03A jump) Current error: 0.1A Product size: 47.63x28.66x23.74mm Installation opening: 45.11x26.00mm Wiring legend Basic operation: Check the metter Wiring as shown below, the meter displays the voltage, the current is 000, the product is qualified Common power supply Test 4~30V loop wiring The thick red wire is connected to the negative pole of the load; the thin black wire is not connected to prevent short circuit. Independent power supply to measure 0~100V loop The thin red and thin black wires cannot exceed 30V Measure the wiring method of solar charging Shopping Note: Longer sensor cables need to be purchased separately