• Self-heating patch designed for the lower back. • Contains multiple cells with thermoactive agents that provide constant heat for 8 or 16 hours. • Effectively relieves muscle and joint pain associated with muscle tension, aches, or osteoarthritis. • Relaxes muscles for more effective pain relief. • Recommended for direct use on the skin, or over clothing from the age of 55. • Package contents: set of 2x4 patches.