The american time™ AllSync Plus clocks are provided in round only high impact black plastic cases with clear polycarbonate crystals and bold, black numerals and minute markers on a non-yellowing white dial. Stylish hour and minute hands are aluminum with a black finish and a red sweep hand. Other bezel colors available. Consult factory. The american time™ AllSync Plus clock is designed to work with multiple master clocks and correction signals. This unit is programmed to identify the signal it receives from the master and operate as that style of clock. Changing clock operation from one style to another is as easy as unplugging the clock from one system and plugging it into another. If needed, changing the placement of 2 small jumpers on the circuit board can change the voltage required to run this clock from 120vac to 24vac or 24vac to 120vac. This clock provides 15 minutes of backup run power without the use of batteries. If a power outage should last longer than 15 minutes, the clock will synchronize to the master clock at the hourly and 12 hour correction cycles.