Perfectly fit with oticon hearing aid: double vent bass domes 6 mm.,Hearing aid domes comes with 2 packs per order, which equals out to a total of 20 domes.,These hearing aid domes fit all ear types, that can be used on behind the ear hearing aids/pocket hearing aids/in-ear hearing aids/sound amplifiers, so you can go on with your life and your everyday activities.,Suggest: Hearing aid domes should be replaced once a month, because the cerumen wax buildup behind the domes.,Important notice:If a perforated eardrum,please don't use the hearing aid domes.