Found this while browsing smart products , not sure how good it is though.
Original Price showing as $39
Works with Google Assistant and/or Amazon Alexa
Secure your home. Detect when a window or door has been opened
Push notifications to mobile device
Working temperate -10°C to 50°C
Includes 3.7V 500mAh Lithium Rechargeable Battery
WiFi connection 802.11 b/g/n, 2.4GHz only