4 oz concentrate for blackening steel. Mix 9 to 1 with water. Makes 5 cups of blackening solution. Works in 2-6 minutes. The pictures show steel objects submerged for 5 minutes. Significant blackening action takes place in 1 minute. Directions instruct to submerge for 2-6 minutes. This one 4 oz bottle of concentrate will make 40 ounces (2 1/2 pints) of solution and will blacken many items. May be stored after it is mixed for blackening at a later date. Will not blacken stainless steel, aluminum, lead, or copper. USA SHIPPING ONLY. I will not ship internationally.