The Laces You&';ve Been Looking For. (TM) The Flexon(TM) lace is a lightweight, low-friction, and performance-oriented flat tubular lace made with buttery soft nylon and engineered to flex with your natural stride. Designed with active rebound using our proprietary non-elastic formulation and production method, it provides just the right amount of recovery to prevent uncomfortable binding in the shoe and promote better circulation for endurance activity and training. Move On with Flexon(TM)