A barrel connector is used when you need to join two male BNC cable ends. This would be handy when you need to extend an existing run of coax.
All machined type connectors
Gold plated contact pins
Recommended for cable with solid center conductor
Good Barrel Connector
Review by Frank Starch on Dec 15, 2012
These BNC Female to BNC Female Adapters (single) work good. These aren't always easy to find in a home improvement store or even electronic store so this is a good source if you need them. Orders arrive quickly.