Power supply: 2 1.5V AAA size battery ( not included ) Low battery indicator: Yes Contract data: Yes Sampling speed: 2 times per second Overload indication: "1" is displayed Max width: 1999 Auto polarity display Measurement method: double integrated A/D switch implementation Operating environment: 0°C~40°C, under <80%RH. Storage environment: -10°C~50°C, under <80%RH. Static Electricity: Approx. 4mA Input impedance: 10MΩ DC voltage 600V +/-1. 0% Clamp dimension: 25mm for open jaw, 35mm for inner diameter popular version. Do not measure DC amperes. Batteries can be removed by customs clearance.