S size
Maximum inner diameter is about 45 mm, minimum inner diameter is about 33 mm.
Width is about 40 mm.
M size
Maximum inner diameter is about 50 mm, minimum inner diameter is about 39 mm.
Width is about 41 mm.
L size
Maximum inner diameter is about 55 mm, minimum inner diameter is about 44 mm.
Width is about 42 mm.
Please watch the details in the pictures.
These sizes may have a little error because it's made by hand.
The ring is only compatible with these cages below
https://www.ebay.com/itm/274992478684
https://www.ebay.com/itm/275498588894
https://www.ebay.com/itm/275499790803
https://www.ebay.com/itm/275503479088
https://www.ebay.com/itm/275515617844
https://www.ebay.com/itm/275515632918
https://www.ebay.com/itm/275515662867
https://www.ebay.com/itm/275516845296
https://www.ebay.com/itm/275516853843
https://www.ebay.com/itm/275522819813
https://www.ebay.com/itm/274896594373