*Coated Teflon inner core* StopTech brake lines consist of a PTFE (commonly referred to as Teflon) inner line that carries the brake fluid, which is then covered with a layer of stainless steel woven braid. The PTFE tube is very resistant to expansion under pressure and maintains integrity with exposure to corrosive brake fluid. *Stoptech braided brake lines protect against the elements of harsh driving conditions.* The stainless steel braid provides support for the PTFE and the weave is extremely durable against incidental impact and abrasion. Next the stainless braided hose is coated with a clear abrasion resistant PVC cover for maximum protection against chaffing and strain relief devices reinforce end fittings. *Testing beyond the limit is our quality assurance* Every StopTech brake line is 100% tested in-house to a pressure of 4,500 PSI. This is almost 4 times the typical line pressure exerted by a production vehicle's master cylinder.