Duplex pin on the left has a 1 1/4" diameter shank x 11 1/2" long. The pin on the right has a 1 1/2" diameter shank x 12" long. Catalogs indicate they were offered in Oak or Locust wood. They could be ordered unfinished, painted or paraffin coated. Catalog listings state they were to be used with duplex pony and duplex deep groove insulators.