Our double duvets are made up to fit a standard 4'6 double bed. We can make up extra long double duvets if required.
The main differences between the various qualities of fillings are weight, insulation and softness. The higher proportion of down there is in a duvet, the lighter, softer and warmer it will be. Subject to correct use, duvets with a higher proportion of down will keep their insulation properties longer.