Material:Steel Surface:Yellow or Zinc Plating(trivalent) Package:Inner 1) Material: carbon steel, alloy steel, stainless steel, colored steel,copper 2) Grade: 4.8, 6.8, 8.8 3) Standards: DIN, ANSI, JIS, BS 4) Finish: chrome plated, zinc plated, nickel plated or black 5) Guarantee terms: the bolt and wing will match each other well.