The display has 5 x 7 single character dot matrix LED with on-board CPU. It has optional green and yellow digits. The standard ATS clock/timer modules display time in 12/24 hour format and count up or count down elapsed time. Control options include on-board push buttons for setting time, sync input for external synchronization such as 59th minute and midnight/noon correction and serial data inputs (TTL and RS232) for sending time and data from a computer or master clock.