"The interlocking design of the Nobbits system eliminates knot stretching when your foot strikes the ground. With the ability to customize the tension at every eyelet set, the Nobbs keep the tension constant, eliminating the forces that cause the knot to unravel and the shoelace to loosen. The unique benefit of the raised 3D Nobb, strategically placed along both sides of the shoelaces, creates the ratchet system - which keeps each knot secure. The raised Nobb also maintains the ideal fit of the shoe. The Nobb rests outside each eyelet in the shoe holding the shoelace firmly in place during each movement of the foot."
Also, ideal for hoodie cords, swim trunk cords, and so much more.