The 50S250 Series from Insulated Wire is a RF Cable with Frequency Range DC to 18 GHz, Cut off Frequency 18 GHz, Propagation Velocity 0.71, Cable Diameter 0.250 Inches, Attenuation 0.05 to 0.40 dB/ft.. Tags: Semi-Rigid. More details for 50S250 Series can be seen below.