FTP Over SSL

Hi All,

Initially, i posted this question to windows general forum but i was told to post here as this is related with IIS/FTP. 

Have one query on FTP over SSL on windows 2012 R2. Everything is set and configured with certificate, However, have one small query on below screen.

If i select "Allow SSL" then user can still connect to FTP without SSL...correct ?

How can we make sure that FTP over SSL is actually being used ?

is the client need to make sure to use the FTP client which support the SSL to use FTPS ? 

Also what port this will use ? 990 ? 

Thanks in Advance

suhag