NSMBT-5/8 CS Stud-Mounted Ball Transfer Unit 5/8" Main Ball 1/4"-20 Threaded Stem Proudly made in the USA NSMBT-5/8 CS Stud-Mounted Ball Transfer Unit, Main Ball is 5/8" Inch, 5/8" Main ball rotates on 3/32" support balls, NSMBT-5/8 CS stud-mounted ball transfer is a heavy duty ball transfer unit, capable of supporting as many as 33 pounds (per unit). NSMBT-5/8 CS features a 5/8" inch ball bearing resting on 3/32 inch individual support bearings, making it ideal for most industrial transfer applications. NSMBT-5/8 CS ball transfer is also useful for a number of different applications where traditional wheel casters are used, including retail store displays.