Fantastic! I placed the 17″ x 19″ sheeting under my fitted bed sheet, and I have been using this product for about 10 nights now. I have felt healthier, with less aches and pains. I have been working at a very physical job, on my legs for 7-8 hours in a day…I can truly say you negative ion product is truly amazing. I feel rejuvenated every morning! Thank you!