supply of digital insulation tester featuredigital insulation tester feature,digital insulation tester features pi (polarization index) measurement auto power off batte ry power indication external connection to 12v/1a power s supply over load protection test time function s etting, automatically run the measurement within the specified time. specifications- rated voltage-500v/ 1000v/2500v/5000v ac/dc, measuring range-500v/1000m!, 1000v/2g!, 2500v/100g! & 5000v/1000g!, op en circuit voltage-dc 500v +30%, -0% -dc 5000v +20%, -0%, including inbuilt lithium iron rechargeable 1 2 volt battery. packing-gift box accessories testing cable, lead, power adapter and etc. [ warranty period: 30 months after the date of delivery ] ] => limited