ATOP lacing system makes it so easy to perfectly tighten or loosen your lace pressure. Turn clockwise click-by-click to tighten and the reverse way to loosen. The correct lace pressure is an especially important balance between a secure fit and not so tight to restrict circulation which may cause cold feet. Other features of Model 806-BC include 200gm of Thinsulate for added warmth, bellows tongue to keep snow out, padded snow cuff, quick dry velour lining, 4mm insole and breathable weather resistant upper material. NNN BC sole required by any Rottefella BC binding.