The Silentnight Deep Sleep All Seasons Duvet has been specially created to help you sleep more deeply throughout the night through every season. One of the biggest causes of sleep disturbance is overheating. The Deep Sleep All Seasons duvet allows to you easily switch your togs so you can stay asleep for longer. This clever design consists of two duvets that can be used in three different combinations. So, whatever the weather you will have the perfect duvet to help keep you at the right temperature.To create the 13.5 tog duvet, use both the 4.5 tog and 9 tog duvets fastened together which will result in a duvet that will keep you cosy and warm during colder months. Alternatively, you can pull the duvets apart and use the separate togs individually in warmer months to keep you cooler. For convenience you can easily pull the duvets apart using the popper fastenings. The 4.5 tog duvet is ideal for warmer summer months, while the 9 tog duvet is great for all-year round use.Both duvets have been generously filled with hollowfibre which creates a soft, cosy and lofty duvet. The polycotton cover is comprised of 80% polyester and 20% cotton, giving you the durability of polyester and the comfort and breathability of cotton.