Accustomed fast delivery! As my summer shoes (Spezialized Tahoe Gr. 47) fit very well, I've tried the defroster from Spezialized at the bike shop around the corner. Have unfortunately not fit because of my high instep. In another dealer then the Northwave Arctic tried in 46, fitted with normal socks but no "air", not in stock in 47. So here, after some deliberation whether Celsius or Fahrenheit ordered in the Arctic 47. Fits with enough "air". Race shoes a few weeks ago on the way to work (daily 19km one way). So far, very satisfied, depending on the outside temp. instead of lighter sock down times with med. compression stockings + lighter function sock or below 0 with ski socks. After it had been "only" to -7 degrees, always pleasantly warm and dry feet. I just got so far with various overshoes "rumgeschlagen". This is now finally over. Shoes are super, can be easily and comfortably adapt to the foot, also running with absolutely rigid sole goes amazingly well!