The Brilliance Booster is salon-exclusive treatment created for extra colour vibrancy. Boosters are used in combination with conditioner or mask. Intended to strengthen and improve the Colour Brilliance Conditioner or Hair Mask. 100ml (3.38 oz). Made in USA. Highly concentrated booster for extra care and optimal colour protection Apply to clean, damp hair before applying a mask or conditioner. Leave for 5 minutes and rinse out thoroughly.