The light flashes for about 10 seconds and then turns off. Does not have a permanent power switch. They flash multiple colors, and you can't set or choose a color (the images looked like white clocks glowed white and green clocks glowed green, but they didn't). Also, don't wear the watch and don't sweat, condensation will get into the watch and you won't be able to see the time and you'll have to wait for it to dry. Overall not bad for the price but not recommended.