Canare L-5.5CUHD 75 ohm Ultra Low Loss Coaxial Cables. Best suited to 12G-SDI transmission.

Key Features and Benefits
Specially designed for 12G-SDI
The max. transmission distance of 4K UHD over L-5.5CUHD single link able to reach 100 m or longer*
* Depending on receiving equipment.
As handy as conventional coaxial cables
Copper foil and high-density tinned copper braided shielding.
Highly-foamed multi-layer PE insulation