NFSBT-1 1/2 CS Ball Transfer Unit 1-1/2" Main Ball Proudly made in the USA NFSBT-1 1/2 CS Ball Transfer Unit, the main ball is 1-1/2" Inch, NFSBT-1 1/2 CSCan be recessed into the surface of the application forming a smooth and multi-directional rolling surface, Unit available with carbon steel balls or stainless steel balls to provide corrosion resistance.