G/GS-16-NX is a 16 AWG, solid thermocouple, extension grade, type NX per ASTM E230 & ANSI MC96.1.

Used on a wide range of applications, thermocouple wire, also known as high temperature wire, is a sensor for measuring temperatures. Two divergent wires are joined together at one end forming a connection that produces electric energy from the two separate temperatures of the wires.