30 boosters.

Here's what you'll find inside:
1 Snow land (basic or dual land, possibly foil)
1 Rare or mythic rare (can be showcase or borderless)
1 Snow common or uncommon, showcase uncommon, or exclusive rare (see below)
1 Foil card of any rarity (can be showcase or borderless)
1 Non-foil card of any rarity (can be showcase or borderless)
7 Commons and uncommons
1 Art card (1 in 20 are foil-stamped)
1 Ad card or card from The List