Microfibre 10.5 Tog Single . This duvet has the closest feel you can get to pure down duvet, in our opinion.It is manufactured using 100% downproof fabric ( this stops the microfibres coming through the fabric, due to tightness of the fabric weave ). This duvet has a cassette construction, which is a series of small boxes with walls which contain the Microfibre. This method of construction reduces cold spots to a minimum.