Weighing in at 5GB, Spotlight Strings is a solo string library comprised of 4 soloists per section and an optional "Ripieno" backup section.
Concert Strings 3 has a dynamic concert string sections and uses up to 16 different players in each instrument. Each player was recorded separately and is additionally programmed in its own group in Kontakt. Therefore, it is possible to implement a true divisi when chords are played. Concert Strings 3 is 10GB in size.
Both libraries require the full retail version of Kontakt.