I bought ours at Home Depot. It is braided reinforcement thread in a gold-tone plastic hose. I had a metal-wrapped one, and it would un-twist when water pressure was applied, enough to kink it at first, then I'd have to unwrap it to continue with my shower. Then when I shut the water off it would twist up the other direction.
P.S. That hose at Amazon costs as much as the entire shower head and hose at Home Depot.