Description: Simply use your voice to control the connected devices by voice assistant. Compatible with Alexa & Google Assistant. When you leave home, it will push notification message to you when the door/window opens or closes, so you can discover the intruder in time. Furthermore, you could share the device to your family members and track the history of sensor activities. APP pushes alarm information, Let you know the alarm information in an instant. Two-way alarm, It will remind you whether it's on or off. Put it on every door in your house and give them a name so you know exactly which door has been opened. You can also install it in your windows, drawers, etc. Specification: Battery: AAA1.5V x 2 (Batteries not included) Wireless Type : 2.4GHz Size: Main body : 7cm x 3.8cm x 1.5cm Small body : 5cm x 1.5cm x 1.5cm Package Includes: 1x WiFi Door Sensor Note: Transition: 1cm=10mm=0.39inch Please allow slightly 0-1cm difference due to manual measurement. Colors can appear different depending on light and how the listing is viewed. Thanks for your understanding and attention. Wish you a pleasant shopping experience!