The Edwards 2000-SC System Clocks are two and four inch Digital Clocks that provide a highly visible time display. The 2000-SC4, four-inch clock, is visible for 160 feet (48.8m) in the bright intensity mode and 150 feet (45.7) feet in the normal intensity mode. The 2000-SC2, two-inch clock, is visible for 110 feet (33.5m) in the bright intensity mode and 100 feet (30.5) feet in the normal intensity mode. Either unit can be operated in either 12 or 24 hour format. Each minute the time display on the clock updates to the master clock time. This ensures that all clocks in the system are in exact synchronization, and that every clock in the system is as accurate as the master clock.