Description: 2-wire 0.28" 3.5-30V DC LED displays Voltmeter. Reverse connection protection technology for avoiding short circuit. Adapt 2-wire : red wire for positive pole and black wire for negetive pole. High precision, low voltage activation and stable operation.Decimal point automatic adjustment. Don't need the power supply, direct use of the test voltage as a power supply. Specification: Product: LED Display Voltmeter Measurement Range: DC 3.5V-30V Material: Plastic + Electronic Component Display : Three 0.28" LED digital tube Display Color: Red/Blue/Green/Yellow Update Rate: 500ms/time Measurement Accuracy: (1% + 2 digits) Operation Temperature: -10~65 Size: 30x12x8.5mm/1.18x0.47x0.33inch (including ears) Wire Length: 10cm/3.94inch Mounting Holes Distance: 26mm/1.02inch Weight: 4g Package Includes: 1 Piece LED Display Voltmeter Note: Color maybe slightly different due to different monitor. The above size is measured by hand, please allow slightly difference. Thanks !