- Base coat and strengthener in one
- Toluene and Formaldehyde free
- Protects dry nails
European Secrets Rock Hard Hardener and Basecoat produces stronger harder thicker nails and can be used alone, as a hardener, or as a basecoat. Creates a moisture shield that protects dry nails. Bonds together a cross-link of fiber proteins. Five times stronger than any other hardener.