Himalayan crystal salts inside the therapy pillow have been used for centuries to improve skin conditions, alleviate Breathing ailments, and strengthen the immune system. They are completely natural and have no harmful side effects. Pillows can be used an infinite number of time because the salts inside never lose their healing power, which makes the pillow an economical choice for natural pain relief. Therapy pillow can be used either hot or cold for two different effects therapy pillow is covered with a removable, washable casing which protects the pillow from dirt, oil, and residue. Himalayan Salt Pillow For Eye & Ear: Himalayan Salt Pillow For Neck Therapy: Himalayan Salt Pillow Medium Size For Back Therapy: Heavy Himalayan Salt Pillow For Spinal Therapy & Back Joints: Himalayan Salt Large Body Pillows: Handcrafted, using high quality natural cotton and filled with Himalayan Crystal salts. Use as is to gently stimulate pressure points, heat in the oven for soothing, moist therapy or keep in the freezer for gentle and effective Cold therapy. Do not microwave.