Practical design with switch button to check battery capacity or real-time voltage, and turn off function. Equipped with alarm, the display flashes when capacity is lower than 20%. Compatible with 12V/24V/36V/48V/60V/72V/84V lead acid battery, ternary lithium battery, polymer lithium-ion battery, 3-series lithium ion battery, storage battery, water battery, etc. Note: Not applicable for lithium iron phosphate batteries, 1-2 Li batteries in series and over 15 Li batteries in series. LCD digital display with PVC waterproof screen protector and green backlight, ensuring clear reading from different angles. Low working consumption, max 5mA. Suitable for garden, home, office and other places, durable for long-term use. Package includes 2 battery meters. Working voltage input ranges from DC 12V to 84V, automatically detects accurate voltage. Specifications: Working temperature 0-40℃; Display: capacity/voltage; Back-light: Green; Product dimensions: 61.3 x 33.3 x 13.5 mm; Mounting hole dimensions: 58.5 x 28.5 mm; Color: as shown; Material: ABS. Only the above package content, other products not included. Light and different displays may cause color difference; measurement error allowed +/-1-3cm.