Highlights of the Set Booster contents include:

• 1 Art card or foil-stamped art card
• 1 Traditional foil (any rarity and includes new-to-Modern reprints, showcase sketch frame cards, retro frame cards, and rare and mythic rare borderless cards)
• 1 New-to-Modern reprint (uncommon, rare, or mythic rare)—there are 42 reprints that are introduced to Modern with Modern Horizons 2. You get one of the 42 cards in this slot.
• 1 Rare (including the five enemy fetch lands) or mythic rare

In addition to all that guaranteed goodness, the Modern Horizons 2 Set Boosters can have an additional rare or mythic rare (so the best packs could have up to four cards that are rare or mythic rare).