Duvets work by trapping warm air. What is Tog?. Polycotton Hollow Fibre Duvet. Duvet Size. UK Bedding Size Chart. Super King 260cm x 220cm 8ft 6" x 7ft 3". King 230cm x 220cm 7ft 7" x 7ft 3". The cover is made from a superior soft polyester and cotton blend, ensuring long-lasting quality.
