Cura-Heat Back Pain Max Size are twice the size of regular Cura-Heat Back Pain and cover a larger area of the lower back, making them more suitable for people who desire warming relief over a larger area and may suffer from severe back pain. Cura-Heat Back Pain Max Size provides targeted, temporary 12 hour warming relief from muscular and joint aches and pains. Just open the sachet and apply to the clothing / underwear where the heat radiates through to the source of pain - increasing circulation, decreasing stiffness and relaxing sore muscles. Fragrance free, non-medicinal and with a thin discreet design, they are ideal to use anywhere.