Features: 2-in-1 Design: This scientific calculator features a notepad with a flip design, including a large LCD writing pad and stylus, allowing you to take notes while calculating. Erasable Notes: Erase notes with the press of a button, or lock them to preserve your work. Comprehensive Functionality: This calculator includes all the functions of a standard scientific calculator and more, making it versatile for students and professionals alike. It supports integrals, derivatives, statistics, and complex number calculations. Portable and Foldable: The foldable design protects the calculator from dust and makes it easy to store and carry. Ideal for junior and high school students, college students, and professionals. Power Source: The main screen is solar-powered; the LCD screen requires a CR2032 button cell battery (included). Specifications: Product Dimensions: Approx. 162x81x175mm Models: 991ES/ 991MS/ 991CNX LCD: 6.5 inches Net Weight: 153g Gross Weight: 255g Material: Eco-friendly ABS Operating Temperature: 0-4℃ Input Pressure: 100x200g Display: Flexible LCD screen + calculator Power: Solar + CR2032 button cell battery Character Color: Monochrome bold script Reflectivity: 25%-3% Note: Due to lighting effects and photography angles, there may be some tolerances in the product. Please understand. Please allow 0-1cm error due to manual measurement. Package Includes: 1 x LCD Calculator 1 x Stylus