Colour change with touch of a button. In this Equus Quartz Clock, you can easily adjust the time by pressing a button on the front & the illumination colour by using a rotary switch on the back. The illumination colour is set on the backside. Measurement range is 12 hours. Operating voltage is 12V. Resolution is 5 minutes. Illumination colours are Blue, Green, Yellow & Red. Black. Installation diameter is 52mm.