I am referring to the line from evap to condenser.Plenty of high pressure ac hoses. The high pressure line from the compressor to the condenser has a rubber hose in it, because if it was metal all the way it would fatigue and break otherwise so it has to flex. I work on ag equipment for a living, and there are many applications where either they are already all rubber lines, to some where they have kits to do away with steel lines and make them all rubber. I've even seen on older equipment where the rubber hoses are held on with regular hose clamps, of course with special fittings. When I finally get my elcamino back together and the duramax in it, i'll probably make rubber lines for it, because they will be easier than making steel or aluminum lines and attaching rubber to them for flex.