The Xiaomi Mi Door and Window Sensor 2 (MCCGQ02HL) helps you keep track of your home's entry points by detecting whenever a door or window is opened or closed. This compact white plastic device connects via Bluetooth 5.1 BLE and works with a Xiaomi Gateway to send synchronized notifications directly to your smartphone, ensuring you are aware of any activity in real time. Beyond simple motion detection, it includes an ambient light sensor and a helpful left-open alert to remind you if a window was forgotten, while the event history allows you to review past activity. Measuring just 34.0 x 32.7 x 14.5 mm, the sensor is discreet enough to blend into any room. It is powered by a pre-installed CR2032 battery and is designed to operate reliably in temperatures ranging from -10°C to 50°C and humidity levels up to 95%. You can easily set it up using the included adhesive stickers for a tool-free installation or use screws for a more permanent fix, making it a practical choice for anyone looking to integrate basic security and automation into their living space.