Synthol Syntholkiné Muscle Pain Patches 2 are thermal patches designed to relieve muscle pain through heat (thermotherapy) and are comfortable and flexible, adapting to the shape of the body. These thermal patches are easy to apply and remove, discreet and odorless. The heat is diffused continuously for 8 hours, with a targeted action on the back, neck and shoulders and should not be used by children under 12 years of age.