The GEL-QUANTUM 90 SD model blends the versatility of a warm-weather sandal with the comfort of our lifestyle sneaker offerings. Featuring nylon straps on the upper. this sandal is also complemented with a buckled fastener for improved stability. Featuring 90 degrees of GEL technology cushioning in the heel. this shoe incorporates the same tooling from our GEL-QUANTUM 90 sneaker for improved comfort.