[Durable polyurethane backstay; Soft flex tongue creates a snug fit between boot and tongue Single-Zone BOA Fit System uses an inner spool to route the laces for a snug fit and easy lace adjustment 3M Thinsulate insulation is constructed from high-loft fibers for water-resistant warmth Room-to-Grow system has a removable footbed and a secondary integrated footbed to expand boots one full size DynoLITE Outsole offers superior cushioning and improves board feel for consistent lightweight support; 1-year warranty]