Multi-function: Calculator is a combination of basic calculator, writing board and pen, which allows you to write while calculating, improving efficiency. The office calculator has an erasable button, which can be reused effectively, reduces paper consumption, and is environmentally friendly. Rechargeable: The calculator writing board does not need to replace the battery. It only needs to be through the C-type cable. The cable only needs 90 minutes to use for 3-6 months per charge, which saves the cost of coin battery and provides a long time for small desktop calculators. Service life. Portable: The portable calculator adopts a foldable design, which is easy to carry in a bag, pocket or purse. It can be quickly disassembled and used immediately as needed. This calculator can be used in homes, offices and schools, using a magnetic stylus to write anytime, anywhere. Mute: This calculator uses a high-quality keyboard, it will not produce keyboard sound, will not work or study quietly, do not worry about disturbing other people in the office, school and home, allowing you to enjoy a quiet moment. colour:Black Material:environmentally friendly ABS Package Contents: 1 x Calculator writing board 1 x stylus 1 x Type C charging cable Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.