BIG HEAVY DUTY QUALITY BOOT.  LINER IS THICK, BUT THAT'S WHY THEY ARE SO WARM.  USUALLY WEAR 12.5, BUT WENT WITH A 13 AS IT'S SNUG AT FIRST WHILE GETTING USE TO THE THICK LINER.  WOULD DEFINITELY RECOMMEND FOR COLD WEATHER.  WEARING IN 20-30 DEGREE WEATHER AND THEY'RE WARM, BUT NOT TOO WARM.  HAVE TO TAKE A CHANGE OF SHOES TO WORK IF SITTING IN THE OFFICE FOR THE DAY.