⭕ Doble M4000 Insulation Analyzer for Power Apparatus Condition Assessment in Excellent cosmetic and working condition. Collection or delivery. The M4000 provides the most accurate test results ever achieved in a diagnostic test system for power apparatus. Dobles superior interpretation of test results will allow your company to make informed decisions with the highest level of confidence. It incorporates breakthrough technology and design that eliminates the problems inherent in other test systems and delivers reliable results, time after time. It offers intelligent software that provides a diagnosis, not just data, so your technicians can make the right decisions every time. No other diagnostic system comes close to the M4000. And for testing your valuable power apparatus, no other decision makes sense.