The Head Speed 21 is part of the Speed Junior Series from Head, the Speed 21 is inspired by Novak Djokovic and features an aluminum frame construction that is ideal for a 3-5 year old. This racquet is a great learning racquet for kids with a larger sweetspot and excellent maneuverability. The 107 sq. inch head size features a large sweet spot and packs plenty of power. The grip size is 3 5/8, which is perfect for this age group.