Ive seen those before... They Started out as Thunderwear then were called the smart carry. I guess they got bought again. I don't think it would be verry comfortable with a full frame. I've heard that if your wearing theese with a pair of kakhis it looks like your trying to smuggle a banna in your pants.
For more information of NFA Gun Trusts or to learn if your state permits ownership of Silencers, SBR's, or Machine guns without your CLEO's signature visit the Gun Trust Lawyer website.