A conditioner unit for conditioning crop material comprises a rotor having a shaft that carries a plurality of conditioning elements 22, a drive mechanism for driving rotation of the rotor about an axis, and a deflector element 24 having a working surface 26 that surrounds at least part of the circumference of the rotor to define a conditioning passage through which crop material is transported by rotation of the rotor. The working surface has front 36 and rear 40 ends that define respectively input and output ends of the conditioning passage. An adjusting mechanism 30 is provided for adjusting the position of the deflector element relative to the rotor, the adjusting mechanism being configured to enable the positions of the front and rear ends of the working surface to be adjusted. The front and rear ends may be adjusted independently. Also disclosed is a mower conditioner device comprising such as conditioner unit.
