MMCX 50Ω RF Coaxial Cable Assemblies Crystek MMCX 50Ω RF Coaxial Cable Assemblies have an adhesive shrink tubing over crimp area, a center conductor of silver-coated, copper-covered steel, PTFE dielectric insulation, a jacket of fluorinated ethylene propylene, and a gold-plated brass connector. The MMCX assemblies feature a DC bandwidth of up to 6Ghz and an operating temperature range of -40°C to +85°C.