Micro Ohmmeter Communication Protocol RS-232 Insulation Resistance Resolution 0.1 microohm to 100 milliohm Maximum Insulation Resistance 2 kiloohm Minimum Insulation Resistance 1.999 microohm Number of Digits 4 Power Source NiMH Battery Includes (2) 4 ft DH4 Duplex Handspikes Automotive Charger and User Guide Battery Battery Charger