Wifi Door Window Sensor: Smart Contact Sensor With App Alerts, Entry, Pack). Product Details WIFI DOOR SENSOR WITHE FREE APP ALERTS: Smart security sensor, "Tuya smart" or "Smart life" app control; when door/window is opened or closed, the sensor will push app notification alerts to your smartphone. Door status, All alarm record history and battery power can be check in app. You can also share Wireless Security Alarm with your family. SUPORT VOICE CONTROL: No hub required;Simple setup! Wifi garage sensor compatible with Amazon Alexa and Google Assistant. For example, you could say, "Alexa, is the "Device' Name " Clsoed/Opened?" PROGRAMMABLE SENSOR: Extend your smart home automation with wifi window sensor; Set up your smart routines in Tuya Smart/Smart life app or Alexa; For example, Automatically turn on your smart wall switches or lights when door opened. EASY INSTALLATION: Without tools, Easy installa the door sensor with included 3M sticker, firm and durable. You can install the alexa door sensor on front doors, garage doors, liquor cabinets, safety deposit box, pet doors and more. The contact sensor is also a good option as a mailbox sensor. LOW POWER WARNING BATTERIES INCLUDED: The sensor door comes with TWO AA Batteries for 1 year monitoring. When the battery is running out, you will receive an App notification, Don't worry about missing any moment. Payment We accept PayPal and credit cards via PayPal. Taxes - US We collect sales tax, as required by law. Shipping We make every effort of shipping within 3 business day of payment clearing. The estimated delivery time is 2 - 5 business days from the shipping date. Policies If you do need to return your item, please contact us via email (you will receive an email when your product ships with additional details - Subject: Important information about your purchase). You will then be provided with a return shipping label and packing slip. Pack the item carefully. Include the packing slip, apply the shipping label, and return the item within 30 business days of the date you request a return, or your return will be canceled. Once we receive your order we will inspect the return. Please allow up to 5 business days of receiving the returned item for your refund.