This 8 digit display calculator uses Faraday's Principle of Electromagnetic Energy to operate.
You will no longer have to buy replacement batteries for your calculator. This battery-free calculator is powered by shaking the calculator side to side.
Shake the calculator so that the magnet slides through the copper coil in the visible chamber around 20-25 times, and enough electricity is generated to operate for 10 minutes.
If the digits on the LCD screen dim, just shake it a few more times to recharge - their calculations won't be lost during recharging.
Includes a comfortable soft grip for ease of use and the usual memory and percentage calculator functions.