APPLICABLE BATTERY: Supports 3-20 series lithium battery packs, 4-24 series lithium-iron battery packs, and lead-acid batteries of 12V, 24V, 36V, 48V, 60V, 72V, and 84V. This product also supports custom mode within a range of 9.5-100V. DISPLAY: The product features a digital LCD display with backlight and a reinforced waterproof screen. It simultaneously displays battery voltage and remaining capacity, allowing users to clearly view the battery status. POWER-OFF MEMORY: After power is disconnected, the voltmeter retains the previous function settings upon restart. LOW VOLTAGE ALARM: The low voltage alarm activates when battery power drops below 10%, indicated by a flashing battery icon, signaling that the battery needs charging. LOW POWER CONSUMPTION: The voltmeter has very low power consumption, with self-current draw below 15mA in normal mode and under 1mA in low-power mode. CALIBRATION: Includes a calibration screw hole for zero bias adjustment by turning the screw, enhancing accuracy and ease of use. EASY TO INSTALL: The voltage meter can be easily mounted on a panel or surface using the included nut and bracket. WATERPROOF & DUSTPROOF: Rated IP67 for waterproof and dustproof protection, providing resistance against water splashes in most conditions. Color: Black Material: Plastic Package Contents: 1 x Battery Capacity Tester Note: Light reflection and differences in display screens may cause slight variations between the color of the item in the image and the actual product. Measurement error allowance is +/- 1-3 cm.