Since I've been asked about this specific brake a few times:
Allen Gun Works in Canada has a Linear Compensator and I believe they will ship to the US.
Main pros: Directs all muzzle blast forward and increases back pressure on the action (good for SBRs or subsonic)
If you don't need all blast to go forward, then you will be better served with comps that can port gas in all directions... Essentially, linear comps spread the recoil over a longer period of time so you get the same amount of recoil but it becomes more of a shove than a punch.
http://www.allengunworks.com/products.html*In the video below and other Canadian videos, bear in mind that most canadian barrels are much longer than here in the US, which magnifies vertical forces of the brakes due to the longer leverage -- has led to some folks misinterpreting the forces applied by brakes like Bulldog on US (~16.25") and Czech spec (~15.4") in previous Canadian videos w/ long barrel length VZ58s...
[Why does this man keep his finger on the trigger ?]