This product is a waterproof tile grout marker pen designed for bathroom cleaning and repair. It is a handy tool for homeowners who want to keep their bathroom tiles clean and looking new. The pen is easy to use and can be used on both walls and floors. With its waterproof feature, it can withstand moisture and humidity, making it ideal for use in the bathroom. The pen is also perfect for repairing small cracks and chips in the grout.