Used successfully by over 600,000 dog-loving bicyclists, mushers and K9 corps around the world, the Springer bicycle attachment allows cyclists to exercise themselves and their pets at the same time. The Springer uses a low-mounted, heavy-duty steel spring to absorb up to 90% of the force of a dog"s unexpected tugs, allowing bike riders to keep their balance, while protecting their dogs from traffic, pedals, and wheels. In addition, the patented safety release frees the dog instantly if he gets caught around a tree or hydrant