Made by gypsum material, safe chalkboard chalks are for use and great for most surfaces, such as white board, chalkboard and more. The ergonomically designed chalk body is convenient for you to grasp and use, suitable for home, school, office and more. Features -Color:Random Color -Material:Gypsum - Size: 19.50X15.00X11.00cm/7.66X5.89X4.32in - This colored chalk set is less likely to leave residue or stains on clothing or other surfaces. - Abundant amount chalks, enough for your spare and replacement, keep a long time use. - Chalk is easy to write with and produces clear, vibrant lines on a chalkboard or other writing surface. - These chalks are comfortable to grasp and smooth to write. Vibrant colors, suitable for long-term use. - This colored chalk is great for use on blackboards, whiteboards, and other non-porous surfaces. Package list: Chalks 5 x Chalk Sleeves 1 x Eraser 1