5/8" inch (15.88mm) Ball Bearing with 3/8" inch (9.53mm) diameter integrated 1" inch (25.4mm) Long Axle, Pin Diameter is 3/8" inch, Bearing Outer diameter is 5/8" Inch (15.88mm), and Width of the assembly is 1" Inch (25.4mm Long), Bearing is made of Chrome Steel.