They are commonly used to extend the video section of a BNC to BNC cable by converting a male BNC Jack back to a Female BNC Jack, simple to use, simply twist and insert\remove! BNC TO BNC Connectors : Pair x2,Pair x4, Pair x6, Pair x8, Pair x10.
eBay
BNC Adapter BNC Connector P57 50ohm Black BNC to BNC Female 50KY Q9 Adapter Connector Accessories BNC Female Adapter Adapter
Aliexpress UK
BNC Male to 3.5mm (1/8") Male Coaxial Power Audio Cable 50 Ohm RG316. 1 x BNC Male to 3.5mm Male Audio Cable. Connector 1: BNC Male. It can transmit audio signal and power in one cable, designed for audio application perfectly.
eBay
BNC Adapter BNC Female Adapter BNC Connector P57 50ohm Black BNC to BNC Female 50KY Q9 Adapter Connector Accessories Adapter
Aliexpress UK
BNC to BNC Lead 2 Mtrs. good quality BNC lead's with factory fitted plugs. RG 58 cable, 50 Ohm.
eBay
BNC Female Connector Solderless BNC Female to BNC Jack Extension Cable Coupler for CCTV Camera Security Surveillance System
Aliexpress UK
Connector 1: BNC Male, Connector 2: BNC Female. 1 x BNC Male to BNC Female Cable. Suitable for TV ,TV Box, LCD Monitor ,CCTV system. 50-2-41 Coaxial Cable. Length: (approx.). : 1m/3.28ft ; 3m/9.84ft ; 8m/26.24ft ( Optional).
eBay
BNC to SMA Connectors SMA-BNC Q9 Straight Convector Adapter RP-SMA to BNC Male to Female for RF Antenna/Extension Cable Kit
Aliexpress UK
BNC connectors used mainly with CCTV systems. BNC MALE TO MALE COUPLER ADAPTER. BNC Plug to BNC Plug. Converts a BNC socket into a BNC Plug.
eBay
Elbow BNC-Elbow BNC HD SDI Video coaxial Cable 75 coaxial cable amera SDI video cable
Aliexpress UK
Easy to install and can be linked to DVR Machine, VCR, DVD Recorder, TV, Capture Card, Multiplexer etc. Video Connection for BNC composite video. 2 in 1 Video/Power Cable with - (1) Video Connection : BNC composite video (yellow).
eBay
Right Angle BNC To Right Angle BNC Spring Cable SDI 12G Video Cable 75 Ω Coaxial Cable Camera Video Transmission Line
Aliexpress UK
© Auroh — CCTV Cables & Accessories. Extend your CCTV run cleanly with theAuroh pre-madeBNC video + DC power extension cable. Available in5m–50m lengths. BNC (Male) to BNC (Male) for analogue CCTV formats — CVBS, AHD, TVI, CVI.
eBay
HD-SDI 12G Camera Video Cable BNC-BNC 75Ω Coaxial Cable Spring Cable
Aliexpress UK
BNC Adapter Male to RCA Phono Female. Convert a BNC socket to RCA Phono for use with a Composite Video Cable. BNC Male to Phono Female adapter. Used to connect the phono cable to BNC port of devices.
eBay
BNC male To BNC Female jack Adapter Jumper Pigtail Coax Cable RG58 cable 12inch~30M
Aliexpress UK