bolkan.nor

hallo,where can I get a magazine extension for my franchise predator? or fit anything from Benelli? magazine to extend Franchi predator / in 12

hey, I have a Franchi in-12 or predator as they call it. Also I wonder if I can get the magazine extension on it? Checking online, but found nothing. hope some of you know anything submit a link, thanks.:) ps, is not good in English, hoho