The Coefficient of Restitution or Bounce affect the reaction off the club face and this is where CO2 pressure of the almostGOLF ball set it apart from all other practice balls. Traditional golf balls are made with compression molded superball rubber and a skin. As a result, they bounce off the club face with amazing speed and velocity. To bring that same bounce without bringing the danger, we had to create bounce, without the weight. We accomplished this with thousands of bubbles that are pressurized inside the ball, so that when you strike the almostGOLF ball, the bubbles compress, then release, just like a superball, but without the distance and danger. Most importantly, unlike other practice balls, the COR rating allows realistic launch angle and spin off the club face to accurately diagnose swing flaws.