75 Ohm F-Type Radio-frequency connectors are used for connecting Series 59, Series 6, and Series 11 coaxial cable to video, CATV, and security cameras. The most widely used connector for residential cable service. F-type connectors do not have center pins. Instead, they use the solid center conductor of the cable as a center pin. For this reason, F-type connectors cannot be used with cables that have a stranded center conductor. Usage of the cable center conductor instead of a pin makes F-type comparatively inexpensive.