Rotax Aircraft engine rotary valve covers  They are for Rotax  Aircraft engine  as in 532  582 or 583 ,  depending which one  you may need , The one piece cover list price is  $ 670.54 and the two piece rotary cover  list price is $ 573.29  The buy it now price  for either one is $ 400.  which includes the priority mail shipping to you and  you only receive one of them and its your choice , again there is no sign of being used  on a engine test stand  for less than one hour each , thanks for looking .