These clocks are designed to be used in industries or common waiting halls like Airports, Railway Stations, Hospitals etc.It uses 4 digits of six inch seven segment displays with super bright LEDs (each segment is made of 4 pixels with 4 LEDs in every pixel). Operates either in 12hrs mode or 24hrs mode. Two keys SET and ALT on front panel are to set the time. Provision to set time through PC COM port or any RS232 Port. Can work as master slave to display synchronized time ( Could be synchronised with a GPS receiver