A Good Choice If You Are Allergic To Dust Mites Since The Pillow Is Machine-Washable At 60°C, A Temperature That Kills Dust Mites. Outer Fabric Of Cotton Breathes And Helps Keep The Pillow Cool And Dry. Easy-Care Synthetic Pillow Filled With Polyester Fibres Which Makes It Soft, Airy And Comfortable To Sleep On.252 thread count.