The ring has an inner diameter of 55 mm.
Fits the linked shells below:
Samsung
iPhone
Vario universal adapter
The Kowa eyepiece ring fits:
25-60xW/30-70xW zoom TSN 770/880/99
20-60x zoom for TSN-770/880
30xW for TSN-770/880
35xW TSN-770/880 40xW TSN-99