Each March of The Machine: The Aftermath - Epilogue Booster Box contains:

• 24 March of The Machine: The Aftermath - Epilogue Booster Packs
• 5 Magic: The Gathering Cards Per Booster Pack
• 1–3 cards of rarity Rare or higher and 2–4 Uncommon MTG cards in every pack
• Guaranteed foil and Showcase card in every pack

Starting with The Brothers' War, Buy-a-Box Promos will only be available for in-store pick-ups and purchase while supplies last as stated in Wizards of the Coast's article here.

Does Not Contain Any Promotional Material