Details: Clairol Professional Crème Permanente Developer is a dedicated developer specially formulated to be used with Clairol Professional's Crème Permanente hair color. Clairol Professional crème permanent comes in 10, 20, 30 & 40 Volume to achieve desired lift. Our SOY4PLEX formula leaves the hair conditioned while ensuring a LONG LASTING, HEALTHY LOOKING coloring result. Get fabulous shades and a reflective shine with the help of Crème developer 20 Volume: Standard lift, up to 2 levels; optimum GRAY COVERAGE Use with permanent, demi-permanent and lighteners Ideal for bowl and brush application