Extech mg302 digital multimeter and insulation tester with wireless pc i f extech mg302 the extech mg302 digital multimeter and insulation tester is a cat iv instrument with a wireless pc interface it combines a 1000v insulation tester with a full featured true rms multi meter in a single compact instrument please see the technical specification for the very comprehensive range of parameters this meter can measure supplied with a remote receiver with usb cable windows reg compatible sof