Descriptions: It is a chalk holder. Easy push the top button to replace chalk stick. Fits for chalk of diameter of 9.5-10mm. Material: aluminum alloy Color: silver Length: approx. 8.8cm Package: Quantity: 2 pieces Features: * Our chalk holder is about 10 mm/ 0.39 inch in inter diameter, 1.3 cm/ 0.51 inch in outer diameter, suitable for 9.5 to 10 mm chalk. Attention: * NOTE: * Our chalk holder could Hold all standard size of chalk. * If you wanna hold a little firm you could shimming the stick of chalk with a piece of paper before inserting it into the holder.