The cover is made of 100% cotton fibre, a natural and skin-friendly material. Climarelle® Cool is a state-of-the-art fleece that provides a faster cooling effect with microcapsules embedded closer to the surface. These microcapsules actively release the cooling effect when needed and allow for a longer dwell time in the comfort zone compared to conventional materials. The fibres of this product are made of a combination of very fine yet very light fibres for maximum comfort with minimum weight. This product can provide a better sleeping climate and restful sleep.