FeaturesEasy-to-use keypadFold-back coverDual power operationAutomatically switches off when not in use3 memory keys, percentage calculator & one-touch sign changeThe large and easy-to-use keypad features three memory keys, a percentage calculator and one-touch sign change key.  Protect the screen with the fold-back cover when in your pocket or bag. The eco-friendly design features dual power operation - solar with a battery backup - and it automatically switches off when not in use.