Kendall 935 Series Foam Conductive Adhesive Hydrogel EKG Electrode, Radiolucent, Tear Drop, Adult, 1.75″. – The high quality foam substrate conforms easily to skin to ensure electrical contact for consistent tracings. – Conductive adhesive hydrogel maximizes adhesion and electrical contact; designed to stay fresh up to 45 days after opening package. – A lift tab located on one edge facilitates easy removal from release liner and patient. – Designed for superior performance including adult stress, holter and diaphoretic applications. – DEHP free, mercury free, not made with natural rubber latex.