• Includes 5 pieces of mini digital voltmeter. • Easy to assemble: small and lightweight, with 3 wires for simple installation and connection. • Safe operation: designed with reverse connection protection for greater safety and stability. • Clear display: 0.28-inch LED display for clear digital viewing and easy operation. • Wide application: ideal for measuring the voltage of 18650 batteries or car batteries with the module's soldered wires. • Specifications: automatic precision adjustment, resolution of 0.01 V for voltages below 10 V and 0.1 V for voltages above 10 V. • Color: Red. • Operating voltage: 4.0-30 V. • Detection voltage: 0-100V. • Dimensions: 30 mm × 11.5 mm × 9 mm. • Installation hole: 23 × 10 mm. • Operating temperature: -10 to +65 ℃. • Working humidity: 10-80%. • Working pressure: 80-106 kpa.