describe: MaterialThis addition, subtraction, multiplication and division stamp is made of PVC material, small and exquisite, cute and practical, easy to carry, and can be reused for a long time. Rotation ModeThis adjustable number, gently scrolling, can print out multiple math problems efficiently and quickly, and can adjust 10 different queue modes to quickly prepare math problems for children. Quick-drying and non-fadingYou can quickly solve math problems for your children, just roll up the math problems and print them quickly, it dries without fading after printing, dries quickly and is very convenient. ReusableThis stamp can be reused by adding ink. After the ink is used up, open the oil cap and drip 5 to 6 drops from the oil nozzle into the oil hole. Once the oil cap is closed, you can continue to use it. Best Teaching GiftIt can quickly prepare math problems for your children at home, do one page every day, improve the speed and accuracy of oral calculation, it is an interesting and meaningful gift for primary school students or friends children ! Package contents: 2 roller stamps (Additional roller delivers ink and packaging box (Subtractive roller delivers ink and packaging box) Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.