Neptune Shop Solar Touch Screen LCD Electronic Transparent Screen Calculator (blue) Totally transparent screen makes it good taste and very interesting! Dont need put in any battery, just need a little Sunshine then you could use this calculator, no matter you are indoor or outdoor, it is not only super easy to save money and very convinient, as it is totally Solar Powered! Ultra-slim clear portable Solar Calculator Touch Screen Calculator without button keys LCD Display Digits, 8-Digit display makes the Slim Calculator easy to use. 20 touch screen keys icon include functions for correcting errors, basic operations and percents.