2″, Black, Dual-Wheel Caster With Threaded Stem (5/16″-18, 1″ Long), 66 Lb Load Capacity, Good For Use On Carpeted Surfaces, Dual Wheels Place More Wheel Surface On Carpet, Wheels Move Independantly In Opposite Directions To Maximize Manoeuvrability, For Use On Ready To Assemble Furniture, Office Chairs, Printer Stands, Entertainment Centers & Other Items.