Stock rubber flex lines expand under heat and pressure, not to mention most of them are tired or sometimes even cracked after years of service. Apex stainless steel brake line provides a consistent brake pressure, precision brake modulation and quicker pedal response Our stainless steel brake lines are made of Teflon inner line, covered with a layer of stainless steel woven braid and clear vinyl sleeve is bonded on top, providing resistant against abrasion and deterioration by environmental elements.