The Extech EX505-NIST is a rugged industrial multimeter with ISO certification, offering AC/DC voltage, current, resistance, capacitance, and diode testing. It features True RMS for accurate measurements in noisy environments, dual sensitivity frequency functions, and a built-in Type-K thermometer for air or surface temperature. The device has a backlit LCD, 1000 V input protection, data hold, and relative measurement functions. Its waterproof IP67 housing is drop-proof up to 6 feet, with safety ratings of CAT III 1000V and CAT IV 600V, making it ideal for heavy-duty industrial and electronic applications.