Elite Trainer Boxes are a great way to get both a variety of Pokémon TCG cards and useful accessories. Each 30th Celebration Elite Trainer Box contains:
Nine booster packs from the expansion
A full-art promo card featuring Nidorina
65 card sleeves 
16 foil Basic Energy cards
Damage-counter dice, a coin-flip die, a plastic coin
A sturdy box with six dividers to store everything.
A player’s guide that provides useful tips for building a deck with cards from the expansion.