The SwaxLax lacrosse training balls are the first and only soft lacrosse ball that are the same size and weight as a regulation ball. The ball was developed by a longtime lacrosse coach and has been field tested by boys and girls in kindergarten through college. The weight of the ball is from 142 to 149 grams and the diameter is 64 mm. The Swax Lax ball is deisgned to help new players develop their skills with more confidence. This ball doesn't bounce or roll away, making for a more productive practice environment. The Swax Lax ball is softer than a hard rubber lacrosse ball, so it creates less fear of getting hurt if a player is hit. You can train anywhere using this ball and have less worry and more confidence.