These Australian licence plates were made to suit the Custom Dynamics LED Frame available from Harley-Davidson Stores. Part Number #2030-0532.
Thread tapped at 8-32 UNC for your convenience.
NOTE: Plate only - Frame sold in seperate listing.
https://www.harleyheaven.com.au/rocd-lpfhrzblp-custom-dynamics-flat-low-profile-number-plate-frame-with-led-illumination.html