Shroud NACRA 17 w/ turnbuckle, is a single shroud for the NACRA 17.
The race shroud is provided with a turnbuckle endfitting. The length of the shroud for a Nacra 17 MKI and the NACRA 17 is the same. Only the endfitting is different.
When you are looking for a set of shrouds, ordering two pieces is necessary.