This is RS485 signal transmission line, made of pure Cu (copper) which is of excellent quality. Little signal attenuation, it has better performance compared with other signal lines which is made of twisted synthetic brass wires.
Of widely use, it can be accessory for devices support RS485 function.
Moreover, it can be customized. If you need one longer than 20 meters, the extra length (above 20 meters), costs USD 1.2 per meter. For example, if you need a 22m line, it would cost you USD 24.4 (20m line: USD 22 + extra 2 meters: USD 1.2*2)