Ultra-powerful, anti-frizz treatment for the most difficult, frizz-prone hair types. Advanced humidity-blocking formula infuses moisture, "waterproofs" hair and delivers super strong, frizz-resisting power. Delivers glassy-sleek blow-dry results and prevents smooth, straight strands from reverting back to natural curly frizzy texture in the worst humidity. Sleek, smooth results last 3-4 shampoos.