The Silentnight 800 Mirapocket Mattress offers a medium-firm feel with 800 individual Mirapocket springs that are zoned to provide targeted support where your body needs it most. This mattress is constructed with sustainable Eco Comfort Fibresâ„¢ which are highly breathable, promoting air circulation for a fresher sleep. It is made in the UK and comes with a 5-year guarantee. The mattress is single-sided and requires rotating every few months.