This is the rarest of Gibson Banjo Ukes. Gibson never really made a UB-5. They offered a UB-4 in both nickel and gold plate.The gold plated UB-4 was a special order item, therefore they were not mass produced. Over the years, collectors began referring to the gold plated UB-4 as a UB-5. My special thanks to Sharry Han in the USA for the information and photographs of this really fabulous instrument.