TENS devices output a pulse current through an electrode stuck to the human body, with these electrode pads a necessary, accessory consumable for massagers and therefore, need periodic replacement. Round electrode pads with a diameter of 42mm offer an excellent flexibility and breathability with no harm to your skin or body. The electrode pad is made of a conductive gel material whose main component is a medical glycerol. Our electrode pads have successfully passed 3 biological compatibility tests to ensure safety and performance, including an in vitro cytotoxicity test, sensitization test and irritation test. These electrodes are harmless and easy to use. The high quality and resealable foil bag also protects extra electrode pads, effectively shielding them against dust and retaining the pad moisture, ensuring a long service life.