UT255 series high voltage clamp ammeters can measure up to 69kV high voltage line current and leakage current. UT255 comes with an insulation rod, allowing professional users to check status of lightning arresters. The wireless model (UT255B) is also able to wirelessly transmit data in real-time up to 30m range. Its clamp can be easily removed from wire by pressing or pulling back the insulation rod.