The 8100-0087 is a 4-inch, four digit CC44S clock/timer/display module with red super-bright dot LED's. Green and yellow LED's are optional. Standard ATS clock/timer modules display time in 12 or 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.