ThermaCare's continuous, low-level heat penetrates deeply and directly to the site of pain and goes on to provide up to 16 hours of powerful pain relief and deep muscle relaxation to help you feel better, all day long. If you're not keen on taking pills for your back pain. When worn for 8 hours, ThermaCare is as effective as taking 6 ibuprofen tablets (2 x 200mg tablets, 3 x daily) when worn for eight hours. It is odour and stickiness free and can be worn comfortably and discreetly under clothing, unlike rubs and creams. ThermaCare is drug free and contains natural ingredients so it can be used alongside oral pain relief products. ThermaCare relaxes tight muscles and helps to improve flexibility. For powerful and targeted long-lasting relief of muscular and joint pain associated with muscle tension, overexertion, sprains and strains and arthritis. Suitable for sufferers of chronic and occasional pain. Ingredients : Heat cells contain iron, charcoal, salt and water. Box Contains 2 pouches, each containing one Thermacare Lower Back Heatwrap, One Size. Keep out of reach of children. Always read instructions.