Help about a Tropic 19 service acrylic Crystal for 5513

[Comex1665]

Hi guys,
I need your help about the service T19. I have done a lot of research and unfortunately I didn't find the outer diameter of the service T19 Crystal. There are a lot of cheap aftermarket acrylic crystals on eBay referring as the tropic 19 but there exist a lot of variations concerning the outer diameter between them. And all of them state it as 1:1 to genuine lol,
As Clarks, as sternkreuz, ofrei and others ..
Many variations of outer diamater exist I have found from 30,2mm to 30,48mm.

Here are my questions:
what is the outer diameter of a genuine tropic 19?
Is there a difference in term of diameter between and original T19 and the service one from RSC ?

Thank you folks for your help !