[garynortheast]

I'm pretty sure that's a FreeFlow end can. I had one on my little gixer 400 and I have one on my Curvy. Much too loud without a baffle but lovely and burbly with a baffle in.
They only get made occasionally. They are apparently made in the same place as Beowulf cans and appear to be unbadged versions of them. They're really nicely made and astonishingly cheap. I paid £112.00 for each of mine, with the link pipe included.