From the back of the box:
Monopoly Deal is the fast-paced, addictive card game where your luck can change in the play of a card!
And the Shuffle Shaker (included) takes the trouble out of the shuffle! Simply pop the cards inside, shake it, and you're ready to DEAL! The Shuffle Shaker ensures you'll never get a bad deal again by mixing the cards thoroughly for a great game.
Use the Shuffle Shaker to carry your cards with you; for storage when you're not playing,and to shake up your other card games too!