Features:  Whole-Home Security at Your Fingertips:  Protect your property from the inside-out, and get mobile alerts when doors or windows open and when motion is detected at home. Set up your entire system without the need for tools or professional installation, and expand your Alarm to fit any home or apartment.  Work With Alexa:  Arm and disarm KERUI Alarm with your voice and get mobile alerts about the Door/Window Open or smoke alarms.  Accurate Alerts:  If thieves invade, W18 WIFI alarm system will issue a 110dB alert ,warn neighbors and deters potential intruders.  Built-in Siren and With 110db wired siren.  6 languages can be switched:  English, German, Italian, Russian, Spanish, French.  24/7 Days Of Professional Monitoring:  If it loses power, it has backup battery to support 8 hours working.  Remote Control, Anytime, from Anywhere:  With a free IOS/Android smartphone app, it can be easily controlled by arming, disarming, and home modes with also a simple remote control.  No emergency information missing:  Auto-dialer function will call up to 6 designated phone numbers in case of a security breach.    Notice:  1. KERUI W18 Only use 2G Sim Card (850/900/1800/1900MHz).  2. KERUI W18 Only Work With 2.4G WIFI Frequency.  3. Batteries are not included.  P831 PIR : CR2450 battery or DC 5V (not included).  D025 door sensor : 23V 12A battery (not included).    Package included:  1 x WIFI GSM Security Alarm System Set