Harwood Textiles 10.5 tog Polycotton Hollowfibre Duvet - 4ft6 Double; Encased in a supersoft microfibre fabric, this duvet has a well-balanced construction and a polycotton hollowfibre filling that provides warmth, without overheating. Its 10.5 tog rating makes it ideal for all year use, keeping you cosy and helping to sleep comfortably. Manufactured in the UK, the duvet can be machine washed..