Add Switchbot Hub Mini To Make It Alexa-Compatible. Switchbot Door Alarm Contact Product Features [Window Door Alarm Sensor for Home Security] SwitchBot Contact Sensor can detect the opening/closing of doors and windows, guarding security of the elderly, children, and pets. With the built-in light sensor, it will automatically trigger the Switchbot Bot to turn on the light when someone moves when the environment goes dark. The magnets need to be aligned with the bottom of the body, and the distance between the two components needs to be less than 1.2 inches (30mm). [Detects People Leaving or Entering the Home] With the built-in motion sensor, Contact Sensor will know whether you are leaving or coming home, making it possible to trigger the different actions you set in the "Scene" in the SwitchBot app. When it detects you leaving home, the appliances will automatically turn off, and when it detects you coming home, the appliances will automatically turn on. (SwitchBot Hub Mini required) [Easy to Install Place It Anywhere] Thanks to the small and wireless design with long battery life, you can install Contact Sensor tool-free and get it set up in seconds. Place it on a medicine box to track whether the elderly are taking their medication, or place it on your pet's cage to know if your kitten has slipped away. [Part of the SwitchBot Ecosystem] Connect Contact Sensor with other SwitchBot products and set up a ?Scene? in the SwitchBot app. When windows are opened, the SwitchBot Bot will be triggered to turn off the Air purifier automatically. [Remote Alert Notification Voice Alarm from Alexa] You will receive a door-open alert notification on your phone if a suspicious person enters the house while you are away. Alexa will start a voice alarm to scare off any burglars, ensuring your apartment security. Shipping: Shipping is complimentary within the lower 48 US States. We Do Not Ship to PO/APO Boxes, HI or Alaska We Do Not Ship Outside of the Continental US All items ship within 24-72 hours of Payment For large items that require Freight shipping a valid phone number is required to call and schedule your delivery Terms of Sale and Feedback: Feedback is extremely important to us and If you are satisfied with our transaction, please take a moment to leave Positive Feedback. YOUR Satisfaction is our #1 Priority! If there are any issues, PLEASE contact us BEFORE leaving a neutral or negative rating so that we may resolve any concerns. We PROMISE we can make you happy if you give us a fair chance. Returns / Concerns: All items qualify for returns within 14 - 30 days of receipt. Buyer is responsible for return shipping on any item that is not damaged Please be sure this is an item you want before making your purchase. Customer Satisfaction is our TOP priority! All items are IN STOCK at time of listing. Inventory changes constantly and it is impossible to maintain a perfectly accurate count of all items. Please do not penalize us if we have to issue you a refund! Thank You For Your Business!