Gossen-Metrawatt-M507C-Metraline-ISO-check-Insulation-Measuring-Instrument-Gossen-Metrawatt-M507C-The-Gossen-Metrawatt-Metraline-ISO-check-M507C-insulation-measuring-instrument-is-part-of-the-Metraline-range-which-has-the-design-philosophy-of-concentrating-on-measuring-one-parameter-&-doing-it-well-This-leads-to-simplicity-of-design-&-speed-of-use-In-this-case-the-parameter-is-insulation-including-insulation-resistance-measurement-with-test-voltages-of-up-to-1000V-voltage-measurement-