Heavy Sleeper Sound Accelerating Alarm Clock Rest assured you aren't going to sleep through this alarm! Alarm starts off with a soft beep and gets progressively louder every four minutes until you shut it off. The numbers on this accurate quartz clock glow in the dark. Req. 1 "AA" battery (sold separately). Steel alloy and plastic. Measures 3 3/4"L x 2 1/4"W x 4 1/4"H.