This is a plug for the antenna coaxial cable that came with the SONY Trinitron KV-14AF1 CRT television. 75Ω RF adapter, for coaxial connection. - Type: 75Ω RF Adapter - Connection Type: Coaxial - Impedance: 75Ω This is a cap for the coaxial cable that comes from the antenna for analog TV broadcasts, and it connects to the analog TV itself. However, it's an antique and unnecessary in modern times since terrestrial broadcasts have long since switched to digital. But if you're still using a CRT television, such as for retro game monitors, you can use it as a dust cover for the RF connection terminal on the back of the TV. It's a genuine SONY Trinitron KV series product, so you can use it as a genuine part for SONY CRT TVs, but I think it can be used for CRT TVs in general. It has never been used and has been stored in a dark place, so it's almost unused with no dust or rust. #RF Switch #Famicom #Retro Games #RC Cable #AV Cable #Super Famicom #Tuner #L-shaped #Conversion Connector