1) Material: steel, iron 2) Surface finish: plain, zinc plated... high quality bolt 1.Good quality,competive price 2.have passed international standard. 3.good surface treatmentNew type iron cellar window Bolt Features: 1) Material: steel, iron 2) Surface finish: plain, zinc plated3) Size: 3", 4", 5", 6", 8" window bolt FG563