Modular document turner and conveyor

In combination, an envelope turner and a document conveyor, said envelope turner having dual interfaces at its receiving end oriented perpendicular to each other, each of said interfaces having a projecting tongue, said document conveyor having a top wall, a groove at the exit thereof for engagement with either of said projecting tongues and a pair of O-ring document conveying belts aligned on either side of said groove, and wherein said projecting tongues include a front wall, a pair of sidewalls perpendicular to said front wall, and a horizontal top wall perpendicular to said front wall and said sidewalls.