STANDALONE ALARM alarm: An on-site alarm with a siren sounds up to 120dB, in conjunction with door/window sensors, PIR motion detectors to form an effective, self-contained security system for apartments. SMALL & PORTABLE : Buzzer the product is small, flexible and easy to carry. So you can easily take it wherever you need it, fix it and it will work for you. EASY INSTALLATION: Wired sound alarm installation options are flexible and convenient. Usually installed in a wall, door, balcony or other places, the installation height of 2.5 meters or more. You only need to paste when installation, no wiring, very easy to use TO USE WITH YOUR SYSTEM: Audible Alarm This product can be used with your system to respond to alarm keypad/console signals. Delivers very loud voice prompts at 120 decibels. This piercing plug-in alarm plugs into your keyboard/console. Note: The data is all manual measurement, please allow 1 - 3cm error, due to the difference of light and d 'display, there will be a certain color difference, depending on the physical object received Delivery quantity: (according to the main picture)