True 4-wire AC sinusoidal measurements effectively avoid the effects of test leads and contact resistance. Two function interfaces, battery sorting function. Built-in battery, Android phone charger charging, low power consumption + multiple power saving options. The test range is up to 200 ohms with a minimum resolution of 0.01 milliohms and less than 5 milliohms. Press HOLD to enable the ZR function to measure internal resistance as low as 0.30-0.50 milliohms. Handmade, the appearance of the right side is overly cautious. high-voltage battery internal resistance tester. True four-wire 1Khz AC sinusoidal battery internal resistance meter 0.00001 ohms --- 200 range. It can measure lead acid, lithium ion, lithium polymer, lithium iron phosphate, alkaline, dry battery, nickel hydrogen, nickel cadmium, button battery, etc. Colour: black Material: plastic Package Contents: 4 x Tester 4 pair x probes note: It is forbidden to input the AC signal and exceed the input signal 100V DC voltage. The machine does not have a charger, charging can be charged with an Android phone charger.