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. Equipped with an alarm design, the battery meter display will flash when the battery capacity is below 20 percent. Fit for different battery: 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: They are not suitable for lithium iron phosphate batteries, 1-2 Li batteries in series, or more than 15 Li batteries in series. LCD digital display: The battery capacity gauge indicators come with a PVC waterproof screen protector and green backlight, enabling clear reading of results on the LCD display from various angles. Low 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 design ensures long-term service, meeting diverse needs and providing a reliable user experience. Package content: You will receive 2 pieces of battery meters with alarm, suitable for use and replacement. Working voltage input ranges from DC 12V to 84V. The device automatically detects and adjusts to the accurate voltage based on the connected battery. Specifications: Working temperature: 0-40°C Display: Capacity / Voltage Backlight: 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 Package contents: 2 x Battery meter Note: Not compatible with lithium iron phosphate batteries, 1-2 Li batteries in series, or over 15 Li batteries in series. The package includes only the items listed above; 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.