The Mi Door and Window Sensor 2 keeps you informed the moment something opens or closes, using a precise magnetic induction sensor to detect open/closed status in real time. A new built-in light sensor adds even more automation — when ambient lighting dims, it can trigger a smart light for a seamless night-time entry scene. Get instant alerts whenever a door or window opens or closes unexpectedly, ideal for keeping an eye on kids, pets, or sensitive areas, and review a full automated event history right from the Mi Home/Xiaomi Home app. Its compact, strong-adhesive design attaches easily to almost anything that opens or closes, and when paired with a Bluetooth Gateway, you can monitor and control it remotely from anywhere.