One other answer
Hi John, I guess that I should try to answer the question a bit better. The upper shroud on mine fits into a slot on the outside end of the spreader tube. This prevents the SS cable from slipping out sideways. There is nothing between the two metals, the aluminum tube and the stainless steel cable. I don't think that chafe is an issue there. The spreader ends and the upper shroud ends are covered with a boot to prevent the tube from chafing or ripping the sail.