These mary janes have shock-absorbing springs in the forefoot and heel that relieve the stress and fatigue of walking or standing better than any shoe available. Tests performed at Michigan State University proved that the patented springs returned up to 96% of the energy from each step that would otherwise be lost to the ground. The downward force deflected and dispersed during each impact is recycled to the wearer as propulsive energy, reducing strain on the feet. Unlike typical foam and gel inserts, these springs will never break down or degrade. The shoes have a full-grain leather upper, a removable leather-covered insole, and slip-resistant outsole. Black. Women's sizes 11-12.