Features: 1.Application Scenarios: Desktop calculators are suitable for home, school, office or shop, and perfect for adults and students. 2.Memo Lock Function and Key Silence: The compact calculator keys feel comfortable in your hand and sound quiet when pressed, making them less likely to disturb others. The "Lock" key function saves your important notes and prevents accidental deletion. It also effectively performs 4 functions for financial, household and accounting assistance for mortgage calculations and tax conversions. 3.Dual Power Supply: The calculator is powered by disposable button batteries, one of which lasts a full year, and the desktop calculator also has a solar panel so you don't have to worry about running out of power even when you're on the go. 4.Notepad Function: Calculator with notepad is great for minimalism and going paperless. You can take notes during calculations, calls and meetings to improve learning and productivity. 5.Environmentally Friendly: The LCD writing pad is designed without blue light to protect your eyes and can be rewritten over 50,000 times without ink or dust, which reduces paper consumption and is environmentally friendly. specification:Item Type: Calculators Material: ABS+LCD Battery: Button cell CR2025 (built in) Capacity: 150 mAh Power Supply: Battery / Solar Size: Approx. 150x90mm/5.9x3.5in Notepad Size: 6 inches Number of Digits: 12 PackageList:1 xCalculator 1 x Instruction Manual