Rare WWII Un-authorized Specialist Rank 4th Grade

A pair of rare specialist rank insignia in near mint condition.Some commanders authorized local the use of specialist insignia. Consisting of one chevron and one to six rockers depending on the pay grade of the specialist (one rocker in the 6th grade, six rockers in the 1st grade). To indicate their specialty, a trade badge was sometimes inset between the chevron and the first rocker.