300 to 75 Ohm Matching Transformer Indoor and Outdoor Use with Weather Boot 3 Pack Balun Antenna Twin Lead Coax Cable Single Audio Video Female Balum Adapter Signal 75/300 Ohm Matching Transformer. Converts 300 ohm UHF/VHF/FM twin-lead input to 75 ohm coaxial cable output to components Convert outdoor antenna connection to coaxial cable input. Includes rubber boot to protect connection from the elements