Hypeflex 3mm Amp Round Toe Boot 100% Sealed seams: Glued, blind stitched and taped for crucial warmth in cold conditions Round Toe design for crucial warmth in cold conditions Superstretch upper for complete flexibility and range of motion New Hyperstretch upper and pull on strap makes it easy to put on and take off in all conditions and boot thicknesses. Dual-density construction. 3mm upper and 2mm footbed allows a thicker, warmer boot without sacrificing board sensitivity and control.