Features LARGE LCD DISPLAY: 3.2 inch 55x57mm TN color high definition LCD screen, providing textured display. Automatic switching of Resistan.ce and voltage range, simultaneous measurement and synchronous display. TESTING RANGE: The voltage range is DC0.00V to ±120V, the internal Resistan.ce range is 0.000mΩ‑500Ω, 6 levels Resistan.ce automatic switching. Suitable for measuring all batteries within and 0‑3000AH. ACCURATE MEASURING: The tester adopts 1KHz AC low Resistan.ce measurement and noise reduction technology, and can measure under the running state of the object. 4 line Kelvin testing method to avoid the influence of wire Resistan.ce and contacts Resistan.ce. CONVENIENT TO USE: No need to distinguish between positive and negative poles during use, plug and play. Equipped with universal DB9 interface, it facilitates users to connect to various battery universal testing devices. It also has a battery filtering function. LIGHT AND BATTERY: With backlight screen display and top LED flashlight lighting, it can operate normally even in dim environments. Equipped with a built in 1250mAh lithium battery for power supply, it can last up to 10 hours of operation. 6. WIDE APPLICATION: This battery internal Resistan.ce tester is suitable for aci.d battery, lithium battery, NiCd battery, alka.line battery, etc., for AA, AAA, button battery, 6F22, etc. Suitable for motorcycles, cars, trucks, boats, RVs, ships, etc. 7. EXCELLENT MATERIALS: The battery internal Resistan.ce tester uses TPR (thermoplastic rubber) and ABS materials, with a thickened design, impact and erosion Resistan.ce, providing comprehensive guard, greatly improving service life. Spec: Item Type: Battery Internal Impedance Tester Product Model: IR502 Screen: 3.2 inch TN Color HD LCD screen with Auto Shutoff Function Battery Types: aci.d Battery, Lithium Battery, NiCd Battery, alka.line Battery Impedance Range: 0.000mΩ to 500Ω Current Range: 50mA-50uA AC Measurement Speed: 3 times/second Measurement SIGNA.L Frequency: 1KHz Resistan.ce Range Test: Auto or Manual Selection Test Method: 4 Line Kelvin Testing Method User Self Calibration: Support Factory Reset: Support Lighting Function: Support Battery: 1 x 1250mAh rechargeable lithium battery, continuous working time up to 10 hours (built in battery) How to Use: Open the package and take out the product for immediate use. packing list: 1 x Tester 1 x Test Cable 1 x USB Cable 1 x User Manual 1 x Storage Bag Package List 1 x Tester 1 x Test Cable 1 x USB Cable 1 x User Manual 1 x Storage Bag