The Killerspin 201-28 2-Star Training Table Tennis Balls 144-Pack includes 144, 40-Millimeter white two-star balls. These balls are ideal for practice and training sessions. The product comes with a 30-day limited warranty. Table tennis is a sport that can be enjoyed by individuals of any age and physical ability. Playing table tennis is a great way to stimulate the brain and promote quick thinking while improving hand eye coordination. Killerspin was built to bring youth and innovation to one of the world"s most beautiful sports, and to serve the table tennis player. The Chicago-based firm produces premium-quality table tennis equipment, sports apparel and media.