Practical designs: The battery capacity voltage indicators feature a switch function button, allowing you to press and check the battery capacity or real-time voltage, then turn off. With an alarm design, the battery meter display will flash when the battery capacity is below 20 percent. Compatible with various batteries: The battery gauge indicators are compatible with 12V, 24V, 36V, 48V, 60V, 72V, and 84V lead acid batteries, ternary lithium batteries, polymer lithium-ion batteries, 3-series lithium-ion batteries, storage batteries, water batteries, and more. Note: Not suitable for lithium iron phosphate batteries, 1-2 Li batteries in series, or over 15 Li batteries in series. LCD digital display: The battery capacity gauge comes with a PVC waterproof screen protector and a bright green back-light, enabling clear reading on the LCD display from different angles. Low working power consumption, with a maximum of 5 mA. Wide applications: These battery meters with alarms can be used in various settings such as gardens, homes, offices, and more. Durable construction ensures long-term service, meeting diverse needs. These practical battery indicators provide a reliable user experience. Package content: 2 x Battery meters, convenient for use and replacement. Working voltage input ranges from DC 12V to 84V. The device automatically detects and displays accurate voltage based on the connected battery. Specifications: - Working temperature: 0°C to 40°C - Display: Capacity / Voltage - Back-light: Green - Product dimensions: 2.41 x 1.31 x 0.53 inches (61.3 x 33.3 x 13.5 mm) - Mounting hole dimensions: 2.3 x 1.12 inches (58.5 x 28.5 mm) - Color: Black - Material: ABS Note: The package includes only the items listed. Other products are not included. Note: Lighting and display differences may cause slight color variations between the image and the actual item. Measurement error allowance is +/- 1-3 cm.