FYI. Use it as you will....
I just bought one of these clamp on muzzle brakes from a business here in Australia. I ordered a 21.5mm to suit my heavy barrel 10FP in 308.
When it arrived I was wrapt with the quality, finish and extra look it gave the rifle. Can't wait to get out and give it a run, hoping to reduce recoil....

http://www.hss.net.au/product_info.php?products_id=1012

The website states - "**PLEASE NOTE: We are able to accept International Orders for this item." Service was impeccable.
I'd like to put a pic on, but I'm not allowed.
Good thing is, it's easily removed if I want to go back to original condition.
cheers,
Dutch.