Collector Boosters are turbocharged booster packs loaded with delicacies for collectors and anyone who wants to style out their deck.
15 cards from Throne of Eldraine:
1 rare/mythic rare with extended art
1 foil rare/mythic rare
9 foil commons/uncommons
3 special frame cards (borderless planeswalkers or "showcase" cards)
1 ancillary card (non-foil version of any ELD card otherwise not found in traditional ELD boosters, such as the Buy-a-Box promo
1 foil token
Throne of Eldraine Collector Boosters come in displays of 12.