Our product is math stamp, made of , which can be and to use. This addition and subtraction math stamp is small and , can be reused many times with ink, the seal is clear, and it will not fade after drying. Features -Color:Assorted Color -Material:Plastic -Size:6.50X4.50X3.00cm/2.55X1.77X1.18in -Note: The volume of the ink bottle is 5 ml. -The Math Stamp is made of plastic material, which can be , and can be used for a long time. -This math stamp, which is made of , is simple to use and speeds up the efficiency of pressing. -Roll the stamp at a constant speed on the white paper, and the math problems will appear in front of you. -Clear printing and no fading, math problems can be easily changed by turning the wheel. -This addition and subtraction math stamp is small and , can be reused many times with ink, the seal is clear, and it will not fade after drying. Package list: 4 x Stamps 4 x Bottles of Stamp Ink