With layers of blended British wool and viscose, a British wool and mohair blend, a cashmere, Yorkshire wool, silk and British wool blend, a British wool, hemp and flax blend and a cotton, hemp and flax blend. The Diamond mattress has a 25000 Cortec™ Quad spring system, contouring HD 4000, HD 2500 and HD 2000 Micro springs. With an in-house woven FR chemical treatment-free mattress cover and four rows of diamond side stitching, this Seasonal Turn mattress has a warming wool winter side and cooling cotton summer side. British Wool & Viscose Blend, British Wool, Hemp & Flax Blend, cashmere, Yorkshire wool, silk & British wool blend, British Wool & Mohair Blend, Cotton, Hemp & Flax Blend, HD 4000 Micro Springs, HD 2000 Micro Springs, HD 2500 Micro Springs, Cortec™ Quad Pocket Springs