These chalkboard chalks are made of gypsum powder materials, safe, and durable. In addition, the gypsum chalk writes smoothly and comfortable to use. Using these chalks, you can make stunning masterpieces on most surfaces, such as blackboard and sidewalk. Washable chalk, easy to erase without leaving traces, easy to clean, will not cause damage to the ground. Features -Color:Assorted Color -Material:Gypsum powder -Size:10.30X2.50X2.50cm/4.05X0.98X0.98in - Washable: The chalk allows you to write smoothly, and easy to erase, can be used to painting on blackboard, sidewalk and so on, easy to clean. - Wide application: This type of chalk is perfect for use in classrooms, offices, outdoor sidewalk and other places as needed. - The chalk is also great for use at home, suitable for kids, children, parents and teachers. - Sufficient Quantity: These chalks have a wide of application, and there are adequate quantity can easily meet your needs. - Ideal Gift: This chalk set is an excellent gift choice for kids who love to create eye-catching art and paintings. Package list: chalks green blue chalks