The 301 is intended to be used with an AC Current Clamp Meter. It provides temporary separation of conductors to facilitate measurement of current. Most 120Vac devices use a two conductor power cord which makes it difficult to isolate a single conductor to make a current measurement. A single conductor is required to make a measurement because a two conductor measurement will cancel each other out.# Features X10 Mode allows for more accurate measurements of low amperage devices# Direct reading in X1 mode# 2mm Voltmeter measurement points# Integrated ground conductor (three pronged US standard plug)# 15 amp capacityApplications# Monitor a devices power consumption# Measure surge current