"YoLink" is a proprietary wireless technology provided by YoSmart. which is based on the Semtech's LoRa wireless technology combined with the YoSmart smart home/building protocol, to provide the most advanced smart home/building devices solution. Compared to WIFI, Bluetooth, ZigBee, Z-Wave, and other smart home protocols, it has the advantages of low-power consumption, long-distance coverage (wall penetration), and anti-interference. It is the first smart building/home protocol that can be very easily setup and is a very low cost but creates a reliable, robust, and more secure IoT network. Requirements:<br> 1. A YoLink Hub (sold separately, used to connect YoLink Siren Alarm to the internet and the Cloud).<br> 2. A smartphone or tablet running iOS 9.0 or higher, Android 4.4 or higher.<br> 3. Quantity 2 AA batteries (not included). Batteries are for short operation during brief power outages; the siren should be plugged-in to 120V outlet at all times. <br><br> Specifications:<br> Voltage: DC 5V/1A (Micro USB) / DC 3V (2-AA Battery, sold separately)<br><br> Alarm Volume:<br> H(high): 110db<br> M(medium): 104db<br> L(low): 100db<br><br> Working Temperature: 0°C~50°C (32°F~122°F)<br> Working Humidity: 0%~95% non-condensing<br><br> Package List:<br> 1 x Siren Alarm<br> 1 x AC/DC Adapter<br> 1 x USB Cable<br> 1 x Quick Start Guide<br>