A Piaggio MP3 350 i.e. brake disc, also known as a rotor, is a crucial component of your Piaggio's braking system. rear TRW Fixed Brake Disc Fixed Fixed MST395 For Piaggio MP3 350 i.e. 2018-2020. By replacing your Piaggio MP3 350 i.e.'s brake disc with a TRW brake disc, you can ensure that your motorcycle benefits from improved stopping power and responsiveness.