More than just another sneaker, The ara Fusion4 leeza adjusts perfectly to your feet every time. Lace-up option offers a custom secure fit. Leeza by ara utilizes Fusion4 technology and a dynergy sole. Fusion4 technology: the 4 in Fusion4 represents the 4 ways in which the foot individually find It's fit: *upwards *to the sides *on the diagonal * downwards. ara styles featuring Fusion4 combine two main components: hi flex upper - multi zone knitted or stretch upper, with a dynamically flexible mode of operation, is designed specifically for the anatomy of the foot. It stretches in all the right places ensuring a comfortable fit while maintaining stability. Dynergy sole - equipped with a special lamellar structure which takes the shape of the whole foot perfectly, and varies in the way that it yields to pressure and motion in the forefoot and heel. Once pressure is removed, the special fins return to their previous shape instantly providing support back to the foot. The result is superb comfort for all day wear, without fatigue.