The RG-59 refers to ‘Radio Guide’ while 59 refers to the diameter size, i.e., .059 and uses a copper plate.
It is recommended for lower bandwidth, (below 50 MHz) applications, including analog video, RF and video surveillance.
With an impedance of 75 Ohms, the cable features a solid 20 AWG bare copper conductor, gas-injected foam HDPE insulation and Dufoil shielding with a tinned copper braid.