The DryBuddy Audio Alarm is designed to alert a sleeping, inattentive, or hearing impaired person by its loud, repetitive trumpet fanfare. This reliable device is easy to use, and very effective. Place the audio alarm near the person to be alerted, and plug its barrel socket. Attach/plug it to any 12V DC alarm device using its 2.5mm x 5.5mm barrel plug or the provided 3/8″ RCA telephone jack adapter/connecter. The power cord is 2 meters (78 inches) long. No batteries are needed. When the alarm device is activated, the audio alarm will sound and alert the user. The alarm has a volume control on its side, which allows the user to set the volume at a suitable level. There is an LED light on the top of the audio alarm, which lights when the alarm is sounding so that the user can see where it is in darkness. An ON/OFF switch on top of the alarm facilitates turning it off. The alarm device can also be turned off to stop the alarm from sounding. The Audio Alarm can be used to wake the sleeping user (such as the Rodger(TM) Wireless Bedwetting Alarm Receiver), or with Telephones for the Hearing Impaired, Alarm clocks, etc. which provide a switched 12V DC 400mA power outlet with a barrel socket (2.5mm x 5.5mm) or 3/8″ RCA telephone socket. NOTE: This Audio Alarm can be used with a 110V-120V AC power source by separately purchasing the DryBuddy 120V to 12V DC 500ma Power Supply. This Power Supply has a barrel socket into which the Bed Shaker’s barrel plug will fit. The Power Supply can then be plugged into an 110V-120V AC 60Hz power source (such as the electric line in a house in the U.S. and Canada) which is switched by an alarm device. This Power Supply can be found on Amazon by searching for DryBuddy DB-PS120 . This allows the Bed Shaker to be used with the DryBuddy Bed Wetting Alarm Power Outlet, Doorbells and Alarms for the Hearing Impaired, Alarm clocks, etc. which provide a switched 110-120V 60Hz AC standard power outlet.