What is the part number for the ear cushion on a HS15/HS30?
Following the Data-Sheet that can be found on the website https://clearcom.com/DownloadCenter/datasheets/Headsets/CC-15-CC-30_Headset_Datasheet.pdf
Ear-Cushion: 202G153
If you need the Off Ear Foam Pad insetad the number is: 202G154
Excerpt from the Datasheet