The Conductive Adhesive Hydrogel provides additional adhesion, consistent tracings, no messy residue, non-irritating and stays fresh up to 45 days out of the package. These are latex free. In addition, none of the packaging utilizes any natural rubber latex.
The packaging has the use by date impressed on the bottom of the envelop. This is roughly three years after manufacturing. Once opened please use within 6 weeks, although experience has shown they still work after months.