This Stay Cool duvet is great for use in every season. The 13.5 tog offers maximum insulation for warmth while also remaining cooling and breathable so you can be comfortable on warmer nights. The 3-in-1 design features separate 4.5 tog and 9 tog duvets that tie together to create a cosy 13.5 tog option for winter months, or can be split out for the summer. Each duvet is enclosed in a 200 thread count pure cotton cover, which offers a soft, breathable feel.