Not sure if they've chaged it recently, but the way Ebonites work is that they measure your hand to get the sizes of fingers, thumb, and span. The drilled thumb slugs have threads on them and the balls are drilled with a few variances in spans with threads to accept these slugs. So when you pick a ball to try, they will give you the grips and slug and insert them into the correct span ball and let you use it until you decide to change.
