3/8" inch (9.53mm) Ball Bearing with 3/16" inch (4.76mm) diameter integrated 3/8" inch (9.53mm) Long Axle, Pin Diameter is 3/16" inch, Bearing Outer diameter is 3/8" Inch (9.53mm), and Width of the assembly is 3/8" Inch (9.53mm Long), Bearing is made of Chrome Steel.