Product Description American Crew Precision 15vol Peroxide Blend is the activator for use with American Crew Precision Blend. This developer activator works with the precision blends, without the use of oils or a long wait. Restores hair to its natural hue. It helps to covered gray spots. FEATURES: In a coloring bowl, mix the American Crew Precision Blend color with the 4.5% developer at a ratio of 1 + 1. About 20 ml are needed for hair 2.5 cm long. tube = 40 ml = 2 applications on short hair or 1 application on long hair. Developer at 4.5% – 15 vol. – 450 ml (11 to 22 colors). Mix 1 + 1.