The blue webbing side of the strap offers more resistance and less stretch, which is what’s needed for static stretching. The black elastic side of the strap provides users with less resistance and plenty of stretch, ideal for dynamic stretching workouts. These elastic pockets along the length of the strap help to gradually stretch your muscles. It’s this unique combination of materials that allows for additional benefits. When the user elongates an elastic loop by stretching muscles, then pulling the webbing strap, they are able to achieve an isometric contraction. The strap is designed for facilitated stretching that uses isometric contractions to achieve greater flexibility than from static stretching alone. At 66″ long, this strap has plenty of space for users to exercise, improve their range-of-motion, gain flexibility and track progress of their work.