Its sad that you think the sts is a ih rotor,,,,,that could not be farther from the truth,,,,,,the deere uses a 3 stage rotor,,,,case one stage,,,,,,,,,Do you know what sts stands forIJIJIJIJ Single tine seperation......totally different than case or anyone else........Deere even has a rock trap,,,,,,integrated into the combine........case it is a extra cost...I have seen this combine in the field,,,,,and at school....yes I am a deere tech.....this combine will make all other rotors obsolete!!!!!!