Babies and toddlers will love moving the sliders back and forth to see and hear all the ocean animals. Each time you move one of the sliders in the book, an ocean animal springs into view and makes a fun sound. But there's more! Move the same slider back again, and you'll see and hear a completely different animal. From snorting whales to playful dolphins, discover the world beneath the waves in this exciting journey through the sea. - Playful and interactive reading experience - Helps build fine motor skills and improves dexterity - Sliders are perfectly-sized for little hands - Includes on/off button to save battery life