A mower which may include: an engine for driving at least first and second cutting blades, wherein the first and second cutting blades are located in first and second cutting chambers of the cutter deck structure, wherein the cutter deck structure may include an inclined surface in the first cutting chamber so that at least part of the inclined surface is located closer to the trim side of the cutter deck structure than is any cutting blade rotational axis, the inclined surface extending downwardly from an upper surface of the cutter deck structure toward at least the trim side of the cutter deck structure, wherein the inclined surface slopes downwardly from the upper surface in a direction away from the side-discharge opening; wherein the inclined surface is configured to help provide a high pressure zone within a rear portion of the cutter deck structure and a low pressure zone proximate the trim side of the cutter deck structure for helping vegetation to be cut to be pulled into the first cutting chamber.