what is bust your brass cool blonde strength repair conditioner? a blonde's best-kept secret. this ultra-violet conditioner tones unwanted brassy hues, while resulting in 2.2x stronger hair* with 55% less breakage.* who it's for all blondes, grays, and silvers 1-4c, + high porosity hair why it's special packed with bond fortifying technology, quinoa protein, plant butters + ultraviolet pigments, this purple conditioner keeps your blonde lookin' cool + strong. bust your brass cool blonde strength repair conditioner is clinically proven to tone, hydrate + strengthen strands, resulting in 2.2x stronger hair* with 55% less breakage​.* safe for strands: clinically proven to be safe for color-treated hair.** *after 1 use when used as a system, clinically tested. **clinically tested when shampoo + conditioner are used as a system. How to use? 1. massage conditioner from mid-lengths to ends. 2. leave on for 2-3 minutes. 3. rinse thoroughly.