Personalized 7th Birthday Baseball 7 Year Old boy Youth Long Sleeve T-Shirt. 7th Birthday Youth Long Sleeve T-Shirt - White has baseball with being seven is a ball slogan quote for kids turning 7 years old. youth long sleeve t-shirt. Shoulder-to-shoulder taping. Youth: S(6/8), M(10/12), L(14/16), XL(18/20)