Proof Research gas lengths

[DocV]

I was talking with an army buddy that shoots 3 gun and he was telling me about a Proof Research build he has with a " rifle+1(squared) " gas system.

I have googled and searched but can not find this term much less a specification for it. Anyone have an idea as to what it is, or what he might have intended?

[Todd.K]

Rifle +2 is a thing. It's 2" longer than rifle.