Hmmmm.
Now I'm starting to wonder if I got ripped off.
I posted this question because I didn't get the 2 round extension with my purchase as the Benelli web site implies.
To quote the site:
"M1 tactical: based on the M1 field, but with integral sling swivels, conventional grip or pistol grip stock, 18.5" barrel with improved cylinder, modified or full choke tubes. Comes with 2 shot magazine extension."
I think I'm going to return the gun tommorow and buy it from another dealer who will supply me with all the included parts!