Made by Oticon. Works with all hearing aids like Phillips, Sonic Innovations, Starkey, Phonak, Signia. Intended to fit Oticon Hearing aid models: Ria, Ria 2, Nera, Nera 2, Alta, Alta 2, Opn 1, Opn 2, Opn 3, Siya 1, Siya 2, OpnS 1, OpnS 2, OpnS 3, Ruby 1, Ruby 2, More 1, More 2, More 3, Zircon 1, Zircon 2, Real 1, Real 2, Real 3, Intent 1, Intent 2, Intent 3, Intent 4. This also works well with Costco hearing aids.