Original set from a vintage Martin acoustic guitar. These are chrome and not nickel plated. Genuine original 1959 set with plated worm gears and small bushing washers. Correct for a Martin D-28, among others. Complete set with all parts with very little use and little play. This is the earliest version and correct for a Martin guitar of this era, however, they make a great upgrade for a Gibson electric.Worm gears have been carefully removed, inspected..., repacked with a modern hi-pressure grease, and properly reassembled. Remarkable that these are ~58 years old and in this condition.$10.99 USPS Priority Mail shipping with Signature Confirmation, USA only.