No set is complete without a Prerelease pack! Core Set 2021's pack is pretty much what you're used to—6 boosters; 1 foil date-stamped card; and an insert. This insert has a timeline of Teferi's life, from his childhood at the Academy to the War of the Spark.
6 Core Set 2021 Booster packs
1 Rare or Mythic Promo Stamped FOIL
1 d20 dice