The hearing aid domes fit with minifit hearing aids: Nera, Alta,Alta Pro,and those hearing aids receivers with MiniFit speakers. Hearing aid domes should be replaced once a month,because of cerumen "wax" buildup behind the wax guard. Our hearing aid supplies comes with 3 pack per order,which equals out to a total of 30 domes each pack comes with 10 domes to use from. These domes for hearing aid accessories fit all ear types,that can be used on behind the ear hearing aids,pocket hearing aids,in-ear hearing aids and sound amplifiers,so you can go on with your life and your everyday activities. Notice:If a perforated eardrum,please do not use the hearing aid domes. Material: plastic colour: As shown Package Contents: 3 x hearing aid supplies Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.