The Sonic BoomTM Alarm Clock is a unique clock that is guaranteed to wake up even the heaviest sleepers. When the alarm goes off, the user can select to wake up to any combination of loud pulsating audio alarm, flashing lights, or shaking bed. The vibrator can produce steady or pulsating vibration pattern for maximum effectiveness. Our patented adjustable volume and tone controls allows you to select the best sound combination to wake you up. The clock display also has an adjustable viewing angle with large, bright green LED numbers for easy viewing. It also has a battery back up for power outages. (9 volt battery not included)