"Designed for Superior performance in stress, holter & diaphoretic applications. Conductive, adhesive hydrogel. Highly aggressive adhesive. Foam substrate conforms easily to skin to ensure electrical contact for consistent tracings. Teardrop shape for easy release and removal." The 535 foam diaphoretic Medi-Trace ECG electrode is designed for high performance stress testing, Holter monitoring, as well as other diaphoretic applications. With Conductive adhesive hydrogel and aggressive adhesive foam substrate, the 535 Medi-Trace electrode molds to the user's skin and provides great tracings.