Gen 2 Rotors are fully enclosed, eliminating trash build-up and having a staggered bar design, allowing a more even flow of material and threshing as material passes over the concaves. The evenly distributed material also reduces the impact on the concaves, reducing the wear of the concave. They are more heavy-duty, allowing inertia to assist in rotation, reducing fuel consumption. Comes with Boron Bars. Boronizing is a thermo-chemical hardening process used to improve metal components’ life and performance to strengthen corrosion resistance and abrasive wear.