As supplied in the past this part is a replacement dust / chain cover. This part replaces the often missing original rubber flap cover that is fitted on the generator cover to prevent chain grease messing the main engine top case. (Part 9 in the attached parts drawing photo) Part has been 3D printed as a solid part in black PETG. Fits both the LC and earlier air cooled RD 250 and RD 400 Any questions please ask.