T, the shunt that is one of the accessories allows that high AMP check not the meter itself. Honestly it is just an analog multimeter and nothing more any tricks it can do is a function of the accessories that come with it, if those are missing then the thing is just a multimeter housed in a big empty metal box. Did you ever look inside the case?
Those things were only available for a short time because word got around quickly about what they were and in no time at all Sears could not give the things away. They sold for a while for, IRC, at $79.95 but the last ones at our local Sears had gotten down to a "clearance" price of $9.95, I remember joking about them with one of the salesmen at the time. The reason I remember them so well is that one year I was given 3 of the darn things as gifts!