Medi-Trace 530 Foam ECG electrodes are designed for superiorperformance in Stress, Holter, and Diaphoretic applications. Conductive adhesive hydrogel. Highly aggressive adhesive. Foam substrate conforms easily to skin to ensure electricalcontact for consistent tracings. Teardrop shape for easy release and removal.Pouch packaging contains individual electrodes.Out-of-pouch shelf life of 30 days.