Switchbot Smart Motion Door Sensor - Wireless Home Security System, Pir Motion [Motion Sensor Detects Your Movements] With a motion detection range of up to almost 30 feet within 110 horizontally and 55 vertically, there?s more than enough range to secure an entire room of your home. You?re also able to customize the sensitivity settings so that you are only alerted to movements that matter to you. With the built-in light sensor, it will automatically trigger the SwitchBot Bot to turn on the light if someone moves when the environment gets dark. [Easy to Install Long Battery Life] Thanks to its small and wireless design, SwitchBot Motion Sensor can be installed and set up in seconds. You can place it anywhere since its magnetic flexible base can be inserted to the bottom and side. The included battery provides up to 3 years of power for round-the-clock security. [Part of SwitchBot Ecosystem Compatible with Alexa] Connect Motion Sensor with other SwitchBot products and set up a ?Scene? in the SwitchBot app. When you come home, SwitchBot Bot (button pusher) will automatically be triggered to turn on the light, and Alexa will say ?welcome home?. When you leave, SwitchBot Indoor Camera will automatically turn on to detect indoor activity while you?re away (SwitchBot Hub Mini required) [Remote Alert Notification] You will receive a notification if a suspicious person enters the house while you are away. [Energy Money Saving] By detecting the room vacant, Motion Sensor automatically turns off the lights, reducing unnecessary energy consumption to save you money.