1.90 Window Self-lock,Window Self-lock,Self-lock 2.Material:Zinc Alloy 3.Surface treatment:Powder-coated or Electrofacing 1.90 Window Self-lock,Window Self-lock,Self-lock2.Material:Zinc Alloy3.Surface treatment:Powder-coated ... manufacturing of zinc and allunmium die-casting for 20 years. 90 Window Self-lock