Made from Sono Wood. Laser Engraved in Mystic Metals warehouse. Choose your size from 1/2" (12mm) through 2" (50mm). Sizes may have a tolerance of +/- 1mm. Plugs are measured by the string wrapping method. A string wrapped around the circumference of the coffin shaped plug is equal to a string wrapped around the circumference of the same sized round plug. Made from natural materials so there may be variances in wood grain/pattern.