This is a 3 oz. (90ml) bottle of super blue by Birchwood Casey. This is designed for bluing polished steel parts and for hardened steels that contain nickel and chrome alloys. It is easy and great for touch up or complete gun bluing! No Heat or other chemicals required. Just make sure all oil is off of metal and apply the super blue and watch the magic happen! It is great for spot touch-ups. NOTE: THIS CANNOT BE SHIPPED INTERNATIONALLY. WHEN CHECKING OUT YOU MUST CHOOSE All Chemicals and UPS AS YOUR SHIPPING OPTION. Chemicals have to go UPS and cannot go to PO boxes.