Barielle Instant Liquid Nail Hardener is for weak, brittle nails. It has a super-strength reinforcer to use as a base coat, top coat or alone to harden nails instantly and provide maximum protection against breakage. It helps you maximize your favorite nail lacquers by making the polish adhere better to your nails. It dries to a clear, glossy finish. Vitamin E, natural protein and sunscreen additives make this formula so effective.