Snuggle up with super king size duvets at Next. These sumptuous extra large duvets are perfectly fit for a super king sized bed, or can be added to a king-size bed if extra duvet is needed. Whether you're looking for a summer, winter or all-season duvet, we have a selection of fillings and tog levels to choose from. Pair with a super king size duvet cover set and you're ready for a sound night's sleep.