The ACR Systems 01-0065 PowerWatch Voltage Disturbance Recorder Starter Pack allows users to monitor and record voltage disturbance information from any North American Power receptacle. Just set up your pre-determined disturbance threshold values or use the industry standard default values and plug it in. This unit is primarily for auditing medical instrumentation, point-of-sale terminals, computer servers, and other sensitive electronic equipment. This unit troubleshoots power line disturbances such as surges, sags,impulses, outages and frequency variations.