This Wake n Shake Curve Alarm Clock is an extra loud alarm clock that has been specifically designed to help those users who are hard of hearing.The alarm clock features 4 alarm options including an audible alarm with flashing LED light and vibrating shaker, an audible alarm with vibrating shaker, vibrating shaker with flashing strobe or a vibrating shaker only. The vibrating shaker is ideal for use under a pillow to help wake even the deepest sleeper. The Wake n Shakes extra large screen and large digits can be dimmed if required, making the clock very easy to read even from distance. This sleek, curved alarm clock is also fitted with a USB port to enable the user to quickly and easily charge their smartphone or other devices. This alarm clock is supplied with a mains adaptor but also features a battery back up as well which uses a single CR2032 battery. Please note that this battery is not included.