Telegartner 50 Ohm RF Coaxial BNC Jack to BNC Jack Adapters 50 Ohm RF coaxial BNC jack to BNC jack adaptors with bayonet couplings. These 50 Ohm RF coax BNC female to BNC female couplers are nickel plated with a gold plated centre contact and are suitable for use in signal, data and video transmission applications. Stock number 156-5700 is a bulkhead mounting BNC jack to BNC jack adapter with an insulating flange and is suitable for use with a maximum panel thickness of 6mm.