Very few details about this product were unveiled, but between three late night tweets, Wizards gave a few clues. They stated in one of the tweets that "It's not a booster, but it is a lair*...*In this case, a 'lair' is a premade box just for you and the very particular things you love about Magic." In another, they revealed a blacked-out tower box with the Secret Lair logo on it.
Wizards of the Coast recently banned a number of key cards found in Throne of Eldraine from the Standard format this week (see "WotC Bans Key Cards from 'Throne of Eldraine' in Standard").
