The BENDER ISOMETER® IR425-D4M1C-2 is an advanced insulation monitoring device designed for unearthed AC, AC/DC, and DC power systems (IT systems). It continuously monitors the insulation resistance to ground, providing early detection of insulation faults to prevent system downtime and enhance electrical safety. This model features two separately adjustable response values, a multi-functional LC display for clear indication of measured values and device status, and automatic adaptation to the system’s leakage capacitance. The IR425 is suitable for a wide range of applications, including control circuits, auxiliary circuits, and systems with frequency converters or DC components, ensuring reliable operation in complex electrical environments.