Hioki insulation resistance testers or megohmmeters feature all-in-one designs including built-in rugged cases and test lead storage compartments. The IR4056 and IR4057 are 5-range, 50V to 1000V digital insulation resistance testers with convenient functions and features to help shorten work time associated with field insulation testing. Key features include 0.8 second response time of PASS/ FAIL decisions, drop proof structure, bright LED and luminous LCD, optional test lead with bright LED lamp to illumi