Please feel free to contact us by email. We will solve the problem as soon as possible. Thank you for visiting this shop, when you come to this shop, there will be more products for your reference. Feature 1. Smart calculator and LCD writing board, 10 digit display, can calculate while recording. 2. Writing board supports repeated writing, so you can write and record information at any time without paper and ink. Environmentally friendly. 3. LCD screen, no blue light, protect your eyes health. 4. With the Erase button and lock button, you can erase the entire screen by clicking the Erase button. Lock button prevents accidental deletion of data. 5. Replaceable batteries, no need to charge and use. Low power consumption and long service life. 6. Small size, can be folded storage, easy to carry. 7. Widely used for home, adult home, office, school and so on. Specifications: Material: ABS. Screen Size: 6 inches Battery: 2 x 1,220 button cells. Size: 6.3 x 6.1 x 0.2 inches (16 x 15.6 x 0.5 cm). Size Folded: 6.3 x 3.1 x 0.5 inches (16 x 7.8 x 1.2 cm). Package Weight: 5 g). Color: Black, White Packaging Weight: 5 g).