The Battle Spirits Explorer Bundle comes with 

4 Battle Spirits booster boxes of BSSB01. (Boxes are $99 each with the preorder discount. Preordering  4 boxes gets you these bonus items:)

1 World Guide Book

4 Promo Pack Vol.1

4 Promo Pack Vol.2

This is a preorder. All items  will ship in April for arrival on or shortly after the street date.