Strength treatment. Hardens nails & smoothes ridges. Extra strength nylon + retinol formula. What it is: An extra-strength nail hardening treatment that protects & strengthens soft, fragile nails. How it Works: Nylon formula fortifies nails & helps prevent chipping, splitting & peeling. Omega 3 & soy formula helps diminish the look of ridges. The Results: Hard, healthy-looking, shiny nails that lasts. Salon tested. No DPB toluene formaldehyde. sallyhansen.com. Made in USA.