2 Pieces of 30mm Ball Bearings with 10mm diameter integrated 10mm (25/64" Inch) Pin Diameter 10mm x 30mm x 123mm 2 Pieces of 30mm (1 3/16" Inch) Ball Bearings with 10mm (25/64" Inch) diameter integrated 123mm (4 27/32") Long Axle, Pin Diameter is 10mm, Bearings Outer diameter is 30mm (1 3/16" Inch), and Width of the assembly is 123mm (4 27/32" Long), Bearings are made of Chrome Steel.