5th Avenue NYC. IPN: Interlock Protein Network. Super treatment for dry/brittle hair. Deeply condition and transform very dry, brittle hair. All Soft Heavy Cream with Redken's exclusive Interlock Protein Network and keratin enrich complex with omega-6 enriched argan oil nurtures hair's protein, composed of keratin, and nourishes hair for intense softness. Hair is silky soft with increased manageability, suppleness and shine. Safe for color-treated hair. redken.com. Guaranteed only when sold in salons. Made in USA.