Building/Tower Clock is composed of clock movement, master clock controller, hands and dial. If you want the clock have more functions, following items can be added in the Building/Tower Clock system:
1.Standby battery. This battery guarantees the tower clock will work for another 24 or 48 hours if power failure.
2.GPS time receiver&data processor. With these equipments, master clock can receive time from the satellites to guarantee the accuracy of the clock at any time and the drift of master clock will be less than ±0.01 second for ever.
3.Chiming system. This system can play various musical chimes (such as westminster) at periodic intervals throughout the day according to your setting.
4.Illumination Function. Basically, there are two ways to illuminate the Building/Tower Clock. First is to install the lamps behind the dial. Second is to install LED lights on the hands & chapter.
5.Monitor Control Unit. This unit will monitor/control the working of master and slave clocks, set the chime interval, chime music and illumination.
6.Automatic Alarm. When malfunction, the malfunction information will be automatically displayed on the monitor screen.
7.Master clocks Backup Function. By adopting primary/standby master clocks system, if the primary master clock in malfunction, the system will automatically switch to standby master clock to ensure the normal work of the tower clock.  

Other Technical Data:
Power Supply: Single Phase , AC 220V±22V, 50HZ
Drift: Day drift≤±0.2 seconds; can be improved to ≤±0.01seconds by GPS system
Chiming accuracy:≤±0.1 seconds with master clock
Master/Slave Clock Time Difference: less than 15 seconds
Master Clock Work Temperature: -10℃~50℃, Required Relative Humidity: 10%~85%
Tower/Slave Clock Work Temperature: -45℃~60℃, Required Relative Humidity: 5%~100%