Interesting series of photographs in different factories around the world. The first one is at our factory http://www.boston.com/bigpicture/2009/02/at_work.html The large clocks in the back are our backlighted Style 4600 design. http://www.electrictime.com/tower_clocks/ The small clocks in front are our backlighted Style 2400 design. http://www.electrictime.com/tower_clocks/4600_flush_backlighted The movements are 24VAC minute impulse. The design is backwards compatible with the originally 1920's line synchronous Telechron designs. They run off our master control which has a temperature compensated oscillator. Accuracy is better than 7 seconds a year - or perfect with a GPS receiver.