Momoyama (1573-1615) or Edo (1615-1868) period, 17th to 19th century The heavy six-plate helmet bowl constructed of iron and covered in a russet-brown lacquer with an ishime finish, the plates coming together on the top forming forming a slight concave, the exposed rivets adorned with floral kirigane (decorative washers), the gold-lacquer fukurin meeting at the six-stage chrysanthemum gilt-copper, brass, and shakudo tehen kanamono, the copper maedate formed as ginger roots and a plum-blossom heraldic crest; the five-lame russet-lacquer shikoro laced in blue with the lowest lame in lacquered leather, and small fukigaeshi decorated with heraldic crests of three chevrons within a circle in gold lacquer With a Tokubetsu Kicho Shiryo (Especially Important Material) certificate issued by the Nihon Katchu Bugu Kenkyu Hozon Kai (Society for the Study and Preservation of Japanese Armor)