Description: Smart window door sensor detector can detect the opening and closing of doors and windows, you can watch the door and windows status and receive the instant alert anytime anywhere via APP. And it can keep you safe and informed all the time. Easy DIY installation, no wiring needed. To install your window door sensors by mounting it on door or window frame. Smart window door sensor is button battery operated and provide long lasting performance. Smart door sensor detector suitable for home, garage, shed, apartment, mobile home, RV, and office, etc.The alarm sensor will turn on automatically when someone pushes the door. You can know if someone enters your home. Perfect gift for your frineds and family as housewarming gift. Package Includes: 1 Set Door Sensor(Large+Small) 1 Piece Manual Note: Please allow 1-3mm measuring deviation due to manual measurement. Due to the different monitor and light effect,the actual color of the item might be slightly different from the color showed on the pictures.Thank you!