LMR Low loss coaxial cables
LMR240 and LMR400 Low-Loss Coaxial Cable
Low-loss coaxial cable for antenna runs where ordinary RG-58 would waste most of the signal — LMR240 for shorter runs and tighter bends, LMR400 for long runs and higher frequencies.
Loss is the whole point: at 2.4 GHz over 20 metres, the difference between RG-58 and LMR400 is several decibels, which is more than any amplifier in the chain will give back.
Supplied by the metre or made up to length with connectors fitted and tested.