The DSA500A Sperry Instruments Snap-Around Clamp Meter is a 5 function, 9 range auto-ranging unit engineered to measure AC Current (40-400 amp), AC/DC voltage (400/600 volt), Resistance (400/4000O) and Continuity. Similar to digital multimeters, clamp meters offer a large range of functions and include LCD screens to display results but they offer the additional unique ability to measure current without having to contact live conductors. This unit features a data-hold switch to maintain the reading on the liquid crystal display maximum count 3999 and auto power-off functionality to extend battery life with a low batter indicator to ensure you won't get incorrect readings due to low batteries. Audible beeper permits easy continuity check Buzzer Sounds at 100 Ohms or less. We consider safety first this instrument has been designed and tested according to IEC Publication 61010 and integrates features such as voltage, current and resistance overload protection and shrouded transformer jaws to further improve safety. This compact, lightweight, yet durable unit measures 7.24 length x 1.73 width x 1 diameter inch and weighs 0.42 lbs. [184(L) x 44(W) x 27(D) mm 190 g] including batteries. cULus and CE certified with a CAT II rating at 600 volt and CAT III rating at 300 volt.