A mixer for an exhaust gas treatment system includes a support body that defines a mixing chamber. A plurality of first blades is arranged in a row, and is disposed along a transverse axis. Each of the first blades extends from an upstream edge, toward a first lateral edge surface of the mixing chamber, to a downstream edge, at a first row angle relative to the transverse axis. A plurality of second blades is arranged in a row, and is disposed along the transverse axis. Each of the second blades extends from an upstream edge, toward a second lateral edge surface of the mixing chamber, to a downstream edge, at a second row angle relative to the transverse axis. The first row angle is less than the second row angle. The row of the first blades is axially spaced from the row of the second blades.