Special booster box ver.1.5 contains 24 packs, 1 of 6 promo cards (box topper), 1 special box promotion pack containing 1 of 3 pairs of promo card pairs.
Each pack contains 12 cards.
With each box purchase, you will receive 1 Special Release Memorial Pack which contain 1 of 4 promo cards. Or with each 2 boxes purchased in 1 order, you will receive 3 Special Release Memorial Packs (equivalent to 1 Memorial Pack per 16 booster packs).
With each box purchase, you will also receive 2 Dash Pack Ver.1.5's which contain 1 of 5 promo cards.
More info here: https://world.digimoncard.com/products/pack/ver3.php