Sperry Top-Sider Men's Mariner II 3-Eye ASV Casual Shoes 100% Leather and fabric Rubber sole Add extra comfort in the heel to a classic leather boat shoe with shock-absorbing ASV Technology. 360-degree lacing system with durable, rustproof eyelets allows you to adjust the width of the heel for a better fit. ASV (Anti-Shock and Vibration) Technology disperses the shock of walking, helping to reduce impact on your legs and back. Shock-absorbing EVA heel cup offers added comfort. Genuine handsewn Tru-Moc construction gives the shoe lasting durability. Non-marking rubber outsole with Wave-Siping pattern provides sure-footed traction on wet and dry surfaces.