Traalarm Compatible With Alexa, Google Home: No Hub Required. Smart Door Window Alarm Supports Wifi Connection And It Works With Alexa Google Home. Supports Voice Control From Google And Alexa. Ideal For Your Children And Elderly: With The Door Alarm Sensor, You Don'T Have To Worry About Your Toddlers Leaving Home Without Notice And Easily Know When Your Elderly Parents Are Leaving Or Coming Home, Can Even Be Clear When Someone Enters Your House, Shop, Office, Etc . Entry. You Can Check Your Home On The App Wherever You Are. Wireless Magnetic Sensor Easy Installation: Easy To Install Home Wifi Window Alarms In Minutes Without Tools Or Professional Installation. You Just Tear Off The Tape On The Door Sensor, Stick It On Your Target Position. Whether You Are At Home Or Away, The Smart Wifi Contact Sensor Will Push Notification To Alert You When The Door/Window Is Opened Or Closed. Low Power Consumption And Long-Lasting Performance: The Wireless Door Sensor Is Powered By 2 X Aaa Batteries, The Working Time Can Last For One Year Without Replacing The Battery. When The Battery Runs Out, The App Interface Will Show Low Battery (Batteries Not Included). Universal Compatibility And Quality Guarantee: Install The Alarm Sensor Not Only On Front Doors Or Windows, But Also On Garage Doors, Front Doors, Safes, Front Doors And More. And We Will Offer You A Replacement Or Refund If You Have Any Problem With Your Door Opener Alarm Wireless Door Sensor.