Requires an Ethernet Tag Manager. 

Wireless reed (Hall effect) sensor for monitoring door/window. Uses CR2450 battery which provides 3x battery life compared with regular Wireless Tags to reduce battery exchange labor. 3 year battery life is expected. 

With matching magnet piece and mounting screws.

Uses low power Hall effect sensor and matching magnet to detect open/close of any gap, works on any door/windows.

• Door/window open/close logging and notification with contact based door/window sensor
• Temperature logging with internal 0.02°C resolution temperature sensor (+/-0.4°C error) from TE France
• Air humidity logging with 0.12% resolution RH sensor (+/-1% error)
• Logging interval programmable from 15 seconds to 4 hours
• Fast too hot/cold/humid/dry notifications independent of logging interval
• Out-of-range/back-in-range notification
• Unlimited storage of logged temperature, humidity and motion event data on cloud (can be deleted any time)

Battery: Installed, CR2450 x 1 (replaceable, where to buy)
Setup instructions
Supports PC/Mac through a web browser, app push notification: iOS 9.0 and above, Android 5 and above. Works with Amazon Alexa and Google Home. 
Notice: This product no longer supports connection of DS18B20 external temperature probe. Use any of the Outdoor Probes instead for this purpose.