Depending on the type of use the rotors can be made as: standard stainless steel tri-lobes, stainless steel bi-lobes, action dual wing rotary piston, gears for models B100 and B105. The stainless steel tri-lobe rotors (5 lobes for B100 and B105) and stainless steel bi-lobes can all be covered with rubber in different compositions. The rotors are interchangeable and should they need to be replaced it is possible to assemble the same type or different types of rotors, irrespective of their shape or the clearances. After replacing the lobes it will be necessary to control or reset the final tolerances.