Our cosiest ever duvet, the Silentnight Warm & Cosy Double Decker 18 Tog Duvet is perfect for coldest winter months. The unique double decker design features two generously filled duvet layers sewn together to create a warm air pocket that retains heat for maximum warmth and comfort. Covered in a soft, comforting fabric that is sumptuously soft and cosy, and doesn’t contain any materials likely to cause allergies.