With layers of blended British wool and viscose, a British wool, hemp and flax blend and a cotton, hemp and flax blend. The Jade mattress features 10,000 of our award-winning springs, including; Cortec™ Quad spring system and multiple layers of HD 2,500 Micro springs. With an in-house woven FR chemical treatment-free mattress cover and two rows of side stitching, this Seasonal Turn mattress has a warming wool winter side and cooling cotton summer side.