An air-activated heat therapy patch for back pain & stiffness Effectively relieves back pain, muscle stiffness & fatigue Generates an average 40?C natural therapeutic heat that targets the affected areas continuously for 18 hours Extra-large sized patch of width 26cm covers firmly & thoroughly the entire back of the body Promotes blood circulation, increases mobility, relaxes tense & sore muscles Non-medicinal, fragrance-free & no side effects Suitable for people who are allergic to medicine Thin & discreet patch, ideal to use anywhere