SMART ALARM SYSTEM for Home Apartment:Alarm Security System is an affordable solution for your apartment security. You have full control over the door alarms for home security through your smartphone and get instant notifications of alarms alert in your house or apartment. CUSTOMIZATION:You can add extra door and window sensors, motion detectors, wireless doorbell, and water detectors to different rooms in your home security systems;It supports expansion of up to 20 sensors and 5 remote controls/keypads, which can be added to the WiFi alarm station DIY INSTALLATION:Easily set up Wireless Home Security System in minutes without tools. The wireless connection devices does not damage the wall. The alarm station should ALWAYS CONNECT to AC adapter.The backup battery works for 8 hours, only as an emergency battery. VOICE CONTROL and WIFI Network:Your Home Alarm System can be easily controlled by Away, Disarm, and Home modes with your voice. Works with Alexa and Assistant. WIFI connection, Only works on 2.4GHz WiFi network, does NOT support 5GHz WiFi networks. Early-Warning Notifications:When someone illegally opens your door or window and enters your house or apartment. smart door sensor will send an alarm to the alarm station, and your mobile phone will receive a real-time notification of alarms alert. Equip every door and window with wifi door sensor to stop burglar. home security systems always give you peace of mind. Colour:White Material:Plastic Package Contents: 1x PIR Motion Detector Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.