Product parameters: Caution: Do not test AC power, do not test voltages above 45V Working voltage: DC5V (do not supply power with overvoltage) Test principle: AC 4-wire method Voltage testing range: 0.001V~45.00V, maximum resolution 0.001V Internal resistance measurement range: 0.1m Ω~6.999 Ω, maximum resolution 0.1m Ω Data recording: Supports recording 5 sets of internal resistance measurement data Voltage display fine-tuning: supported Internal Resistance Display Fine Adjustment: Supports Automatic shutdown: supports 1-9 minute standby time adjustment Backlight brightness: supports 1-9 levels of display backlight brightness adjustment Color: Gray Material: ABS Package Contents: 1 set of voltage internal resistance tester Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.