SERUM BRUSH HAND SCALP AND SHAMPOO BRUSH IS USED WITH ACTIVE INGREDIENTS FOR OPTIMAL DISTRIBUTION. WHETHER LIQUID HAIR BOOSTER, THICKENING SHAMPOO OR ANTI-HAIR LOSS ELIXIR : FOR MAXIMUM EFFECTS, YOU MUST DISTRIBUTE THE ACTIVE INGREDIENTS OPTIMALLY ON YOUR SCALP. EXACTLY EASY TO ACHIEVE WITH THE SERUM BRUSH. SCALP AND SHAMPOO BRUSH.