A real thing of beauty... This unit has 50 miniature piezoelectric drivers for needles in 8 by 2 pattern (computer Braille, as opposed to the more traditional 6-dot Braille, though the device can be configured to support that as well). These drivers were made by Tieman, are incredibly precise and complex and use high voltage to power the elements. The unit is powered from 12V DC with an internal NiCd battery and DIN connector for charging and operation.