Beware of Imitation Aramith Balls
While most other polymer and polyester balls try to imitate the look and/or packaging of the Aramith product line, none offer the quality of phenolic resin. Beautiful in the box, most look quite different only a few hours later.
Beware of imitations and check for the Aramith logo and/or the Aramith name on the box to be sure you've got a genuine Aramith phenolic ball set.

The American Poolplayers Association (APA), the world's largest pool league, has appointed Aramith as the exclusive official ball for all its tournaments.
Looking for rules on how to play?
Billiard Congress of America Rule Book has a wealth of information including rules as well as many specifications and guidelines.