Aircell-5 is only 5mm thick and has a surprisingly low attenuation, useable up to 10GHz.
The solid center conductor is made from oxygen reduced copper, double shielding with a copper braid and a copper foil. The insulator is made from a special compound of LLC-PE with very low losses.
And the large advantage: with the same dimensions as RG-58 no special connectors are required, all connectors suitable for RG-58 can be use.