I think this is a Stealth silencer (or not in this case) unit.
Header size is for pre '08, was fitted to my 2007 Uly.
Exhaust exit is R/H side, 3 1/2" pipe.
Some staining to the stainless, should clean off with Autosol or similar if you wanted it gleaming.

One of the captive nuts for the chin spoiler has come adrift, but it is the rear left one, so accessible with a spanner. I still have the captive nut assembly.

The two very front ones are also missing (but may not have even been there in the first place).

With the four side bolts in place the chin spoiler is completely secure.

£150 please, would prefer collection but could probably stuff it in a box and lug it to the Post Office

That looks like a Stealth!

Aye, that's what I thought too, but not absolutely positive so didn't want to put it in the actual title of the post.

You're right about it being loud. I have one on my xbs. It's been on about 8 years and any packing has long been blown out. That's the only thing wrong with fully welded cans. They can't be repacked. It still looks like new though