Duncan YoYo Kit - Imperial Green Yo-Yo, Mult-Color Yo-Yo String 5 Pack, and Yo-Yo Trick Book The Imperial Yo-Yo is Great for Beginners Learning Basic String Tricks. Featuring a narrow string gap, steel axle, and durable plastic body. String Multi-Pack contains 5 Replacement Strings in Assorted Colors. Strings are Made of 100% Cotton. Yo-Yo Trick Book Has Over 660 Tricks. Includes Bonus Free Hand Section. Good Old Fashioned Fun for Kids and Adults Alike.