NoiZfree Twin Binaural Hearing Aid Compatible Headset for Cell Phones 2.5mm jack is compatible with cell phones (may require an adapter) and standard telephones with a headset jack hearing aid must be t-coil equipped includes bonus 3.5mm adapter for use with audio devices ***PLEASE NOTE-IF OPENED, THIS IS A NON-RETURNABLE ITEM DUE TO HEALTH DEPARTMENT REGULATIONS***