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 colouring 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 / Roughly 2 applications on short hair or 1 application on long hair Developer at 4.5% - 15 vol. - 450 ml (11 to 22 colours) Mixing ratio 1:1 Break time: 5 minutes