Mower (1), has a plurality of mowing elements (2), forming a mower bar (3), a roller conditioner (4), behind the mower bar (3), and an upper conditioning roller (5) and a lower conditioning roller (6), the lower conditioning roller (6) is rotatable about a lower, positionally fixed axis of rotation (8), wherein the upper conditioning roller (5) is rotatable about an upper, shiftable axis of rotation (9) that, as a result of shifting the upper axis of rotation (9), a gap (7) between the conditioning rollers (5, 6) is changeable, wherein the lower conditioning roller (6) and the upper conditioning roller (5) are coupled to each other via a scissors-like transmission (10), and wherein first and second transmission parts (11,12) are coupled to the lower conditioning roller (6) and the upper conditioning roller (5) respectively and are operatively connected to each other and are shiftable in a scissors-like manner.