The Columbia Whit Dot bowling balls have become the ball of choice for a spare ball by many bowlers. They are polyester shells with a simple flip block. These balls can hook on very dry lane conditions. However, for the most part they are used when shooting for single and some multi pin spares. If you do not see a ball in the weight you desire it most likely means it is not availble at this time/ The Columbia Logo visaball is included, but is more expensive than the standard White Dot series.