Door And Window Sensors Wifi,Smart Door Open/Closed, Battery Not Included Product Details Wireless connection?By connecting WIFI and mobile phone connection, whether you are where, Instant notification to your phone immediately when door or window is opened or closed. Multipurpose Sensor:Install the Alarm Sensor not only on front doors or windows, but also on garage doors, liquor cabinets, front gate, safety deposit box, pet doors and more. Easy Installation:Very easy to install via the tapes mount on door or window frame. Tapes and screws included, everything you need to get started is in the box. NOTE: Make sure that the sensor and magnet are aligned and gap less than 10 mm. Compatible with Alexa Google Home:No hub required and No fees charge. Product quality and service:Our products are 100% tested and ensure that all products are qualified products before leaving the factory. Please rest assured to purchase and use. 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.