A rectangular baler having a bale chamber, a compacting plunger and a guide system having at least one guide assembly including a guide element, and a threaded shaft and nut for positioning the guide element, wherein, for receiving said threaded shaft, an elongated slot is provided extending in a slot direction making an angle between 1 and 85 degrees with respect to the discharge direction, the threaded shaft being arranged in an upright position perpendicular to the slot direction.
