Killerspin 2-Star Balls are a perfect option for amateur players ready to improve their game. This 6 pack of standard size 40-milimeter balls is constructed of high grade materials for consistent and quality play every time. Professional or leisure play and perfect for the novice to serious player. They are a match made in heaven with Killerspin Throw II Robot. Available in white or orange. Killerspin was built to bring youth and innovation to one of the world's most beautiful sports, table tennis.