Duck Feather & Down Super King Duvet 13.5 Tog Feather and Down duvets contain a mix of approximately 85% small feathers and 15% down clusters. The difference between feathers and down clusters is that the feather is long and flat with a quill running along the centre and thicker strands attached to the quill. The long flat shape means more filling is required to provide the same insulation as down resulting in a heavier feeling duvet with more bulk this gives the feeling of weight.  All of Norther Feather duvets are box stitched to ensure an even distribution of the filling throughout the duvet and prevent it all falling to one end. They use only 100% cotton outer casings which are 233 thread count and do not allow the feather or down to permeate through.  Product Dimensions: 260 x 220cm  Material: 100% Cotton outer.