CESS F-Type Balun 300-75 ohm TV Connector Antenna Matching Transformer - F 300/75 ohm Plug (4 Pack) FM Antenna Matching Transformer 300 to 75 ohm / 75 To 300 ohm. Quick Connect "F" Matching Transformer. Converts 300 ohm to 75 ohm. Use to Convert the 300 ohm Twin Lead Wire to a 75 ohm F-type Connector. Push-On "F" Type Balun