Ammeltz Yoko Yoko Back Pain is a non-medicinal heat therapy pain relief in the form of patches. Air-activated body warmer generates heats up to 40°C. The natural heat will last for 8 hours. Large size heat patch of length and width 22 cm x 9.5 cm can stick fitly and firmly around applied part such as the back. Comfortable heat sensation. No fragrance or medicinal ingredient is formulated. Thin, odourless and simple design, it is convenient to put into pocket and bag, as well as enable the user to use anywhere and anytime.