The main function of this device is reading text documents from SD/MMC cards. It's based on ATMega32 microchip with Petit Fat libraries. The display is from Nokia 3310 phone because of it's high contrast and low energy consumption. It's controlled by 3 buttons: up, down and ok. The device is powered with a small AAA battery. The whole idea was to make a very small device which can be easily to hide in a hand.