APK Identification TENS electrodes are self-adhesive electrodes for TENS and electrical muscle stimulation therapy. Each electrode is built from a conductive carbon layer, a skin-friendly hydrogel and a soft non-woven cloth backing, with a PET release liner protecting the gel until use. The carbon layer spreads the current evenly across the pad, and the hydrogel keeps contact with the skin for comfortable, consistent stimulation. They are supplied with a female pigtail lead wire, in square, round, rectangular and oval shapes to suit different body areas and different devices. Custom sizes, shapes and OEM branding are available on request.