Practical helper: just check the current battery level | It is very suitable for determining whether the battery is consumed in the drawer, etc. Can quickly measure the battery voltage and digitally display the test result. Flexible use: suitable for AAA, AA, C, D, 9V block and button batteries and other types of batteries | There are two different points on the device, for measurement, 1.5V + 9V batteries can be used The operation is simple: insert the battery according to the polarity direction - read - done | Cursor adaptable to different battery sizes | Three-color simulation shows clear results | No additional power supply required Easy to read: The design of the portable device is easy to read. No battery required: The battery tester is activated by the battery to be tested and can work without a battery. Test battery life anytime, anywhere.