This EZT belt that came today was advertised as "Genuine Husqvarna Belt 539120806 30 Zezt" but doesn't look like my spare never-used OEM deck belt (585054001) that I bought two years ago. The deck belt looks sorta' like ladies' stocking material was melded into its surface, giving it sort of a brown appearance, and has the full nine-digit part number stenciled onto it. The EZT belt I received today is just a plain black and the part number stenciled onto it is only 120806 when the full part number is 539120806.
The original part number was 120806 which is what would of been stenciled into the belt prior to the part number changed a few years back when they added the 539 to the part number. So would say it is actual OEM.