This ingenious alarm clock from Acctim has been future-proofed with dual power sources. It uses solar energy by day and a battery by night, extending overall battery life dramatically. The clever power system is also combined with the clock's innovative Acctim Smartlight® technology which automatically illuminates the display for easy night time viewing.Catering to your personal comfort, the clock also has a high/low brightness control and its display has an additional blue backlight that illuminates when the button is pressed. With a crescendo alarm that's sure to wake even the deepest sleepers, this fantastic alarm clock also comes with a 1 year guarantee.