The Buddy Hall Cue Guide has been endorsed to bear the BCA Seal of Approval. The Buddy Hall Cue Guide was developed in 1986 by Ruben Rodriguez, who came up with a simple device that lets you work on that aspect of your game even if you don't have a table at home. Every pool player on the planet wants a straight level stroke. The Buddy Hall Cue Guide [Professional Model 3/4" inside diameter X 5" tube length, from Rodriguez Enterprises, is a training aid designed to improve and perfect a player's stroke. Made in U.S.A. Cue ball not included.