Rusk Universal Shine Enhancing 40V Cream Developer in the 33.8 fl.oz size is a high-strength developer commonly used in hair coloring applications where significant lifting or lightening of the hair is desired. The "40V" designation indicates the volume of peroxide in the developer, with 40V being a strong developer used for lifting natural hair color by several shades or for achieving very light results. This cream developer is formulated to work with hair color or lightening products to activate color molecules and ensure consistent, vibrant results. It provides ample product for multiple applications, making it suitable for both personal and professional use. Users typically mix this cream developer with their chosen hair color or lightener according to the instructions provided with the specific hair coloring product. Its creamy consistency ensures easy mixing and application, resulting in smooth and uniform coverage.