MD-334R is a kind of alarm device with strong popularity. Its power from the adapter or external lithium batteries via wireless signal. Its communicate with alarm panel, detector, remote etc. Which work with the same frequency as the siren and achieve flash light and alarm sound when alarm occurs. And it also give prompt sound when the remote which have code with the siren to arm or disarm. This siren has anti-temper function to avoid intentional damage or dismantle. When alarm happens it make high alarm sound. Commonly used in the outdoor of the house, office, factory, shops etc.