The Zen is a plain toe slip-on. The upper is mesh and manmade nubuck or mesh and canvas. The lining is breathable mesh. Our Dual Comfort technology is a unique combination of two foam compounds that you have to feel for yourself to believe. The top most layer is created from memory foam, which forms to your foot for instant comfort. The bottom layer is created from an open cell foam that absorbs the pressure of each step and provides all-day comfort. Direct Inject Lites are our lightest outsoles yet and are created from millions of air bubbles to make the compound as light as possible, while still providing exceptional durability for long-lasting wear. The outsole is attached directly to the upper.