Digital Phonak Virto M90-312 Hearing Aid, In The Canal. Supplied with batteries 312. The Digital Phonak Virto M90-312 Hearing Aid is a high-quality, in-the-canal device designed to provide exceptional sound processing capability. Produced by the reputable brand Phonak, this hearing aid is functional and has been tested for optimal performance. It is ideal for individuals seeking daily living aids to assist with their hearing needs, ensuring improved communication and overall quality of life.