The Phonak CeruShield ™ Disk is the new Phonak filter system specially designed for the Phonak speaker 4.0.
The CeruShield Disk protects the speaker against cerumen.
These filters are not suitable for the other Phonak speakers.
Below you will find the instruction video of how to replace the Phonak CeruShield Disk:
https://youtu.be/qGMbmUzi2uQ