Truguard, 2 pack, 2″, black with grey soft tread, dual-wheel caster with 1-1/2″ x 1-1/2″ plate, 66 lb load capacity, for use on tile, wood floors or carpet, dual wheels place more wheel surface on carpet, wheels move independently in opposite directions to maximize maneuverability, for use on ready to assemble furniture, office chairs, printer stands, entertainment centers & other items.