Feature:1. True fourwire 1Khz AC sinusoidal battery internal resistance meter. The maximum resolution of internal resistance is 0.00001Ω, and the maximum measurement range of internal resistance is 200.0Ω.2. The maximum voltage resolution is 0.00001V, and tested lithium battery voltage can display to 0.0001V, ensuring high sensitivity. It can measure positive and negative voltages.3. It can measure lead acid, lithium ion, lithium polymer, lithium iron phosphate, alkaline, dry battery, nickel metal hydride, nickel cadmium, button battery, etc.4. Use ZR function to measure internal resistance below 5 milliohms with higher accuracy.5. Made of high quality ABS material, sturdy, durable and long service life.Spec:Condition: 100% Brand NewItem Type: Internal Resistance Tester Material: ABSColor: As shown in the pictureBattery: batteryModel: 18650Battery Capacity: 2000 mah Internal Resistance Measurement Format of accuracy ±([Percentage of accuracy] [Least Significant Digit]) Range Resolution Accuracy 20mΩ 0.01mΩ 0.7%+7(When ZR is enabled) 200mΩ 0.1mΩ 0.5%+5 2Ω 0.001Ω 0.5%+5 20Ω 0.01Ω 0.5%+5 200Ω 0.1Ω 0.6%+5 The above data is in the range of 5%-95% of the gear position. If it is not within this range (less than 5% gear range range, or greater than 95% gear range range), the error may be greater than the above accuracy. Voltage Measurement Range Resolution Accuracy ± (% reading +% range) 1V 0.00001V 0.15+0.015 10V 0.0001V 0.15+0.010 100V 0.001V 0.15+0.015 Positive and negative symmetric error±(0.012%+ 5 digits). Temperature drift