... digital RF technology 3.128*64 dot matrix LCD display Professional Voting System specs as below:General Specs: Transmission distance > 100 ... , Vista, and Windows 7 and compatible with PPT 2003,2007 and 2010 Complete text input functions. Keypad handles alphabet, standard punctuation, numbers ... names, and reduces the risk of cheating in large classrooms. Professional Wireless Voting Pads