Nail Expert Black Diamond HardenerNail Expert Black Diamond Hardener, your key to achieving harder, more resilient nails enriched with the power of black diamond particles. Features: Diamond Reinforcement: Infused with double patented ingredients, this hardener contains micro diamond particles and a specialized hardening agent that work in harmony to instantly fortify thin, weak, and brittle nails. They create a robust, glossy shield that enhances nail strength. Ultimate Protection: