MS8221A MultimeterThisinstrument has been designed according to IEC1010 concerning electric measuringinstruments with an overvoltage category (CAT II) and pollution 2.To get bestservice from this instrument, read carefully this user's manual and respect thedetailed safety precautions. Specification:Environmentconditions: 600V CAT.III and 1000VCAT.IIPollutiondegree: 2.Altitude