Kitty Yo-yo Strings. Kitty Strings are new strings designed with the player in mind. Designed to be much longer wearing than normal strings, good for slack and suicide tricks. They are 100% polyester yo-yo strings in neon green, neon orange and baby pink. Kitty strings are type 10 yoyo strings. Kitty strings have been used by John Ando, who won the World 2008 1A division.