YoLink Smart Home Starter Kit: 4 Door/Window Sensors & Hub Kit, Compatible with Alexa, IFTTT, App for Remote Monitoring, Control and Alerts, Door Still Open (Door Left Open) Alerts
Brand: YoLink
Color: 4 Door Sensors with Hub
Product Requirements:
The smartphone or tablet able to run iOS 9 or higher; Android 4.4 or higher.

Features:
Real-time Status - Monitor the real-time state of door via YoLink App.
Open Remind - Remind you while the door is open for a set up time.
Battery Status - Update battery level and send low battery alert.
YoLink Control - Trigger an action of certain YoLink devices without internet.
Automation - Set up rules for “If this then that” function.

Specifications:
YoLink Hub
Input: 5V DC
Maximum Current: 1A
Working Temperature: -20°C~50°C (-4°F~104°F)
Humidity: 0~90% non-condensing

YoLink Door Sensor
Button: Set Button
Voltage: 3V DC (2* AAA battery)
Trigger Distance: 18-25mm
Environment:
Operating Temperature: 0°C~40°C (32°F~104°F)
Storage Temperature: -20°C~70°C (-4°F ~158°F)
Operating Humidity: 10%~90% (non-condensing)
Storage Humidity: 5%~90% (non-condensing)

Package Content:
1 x YoLink Hub
4 x YoLink Door Sensor
World's Longest Wireless Range: Powered by LoRa technology, the long-range yet low-power system offers the industry’s longest receiving range in the market (1/4 mile). Our long-range coverage enables its use in areas challenging for most residential Wi-Fi systems, such as basements, outdoor porch/patio areas, sheds, free-standing garages, even remote outbuildings on your property.
Early-Warning Notifications - Receive real-time early-warning notifications in the form of smartphone banner alerts, limited SMS/text messages, and emails, each optional and configured per your needs; Please note: YoLink Door Sensor does not alarm or chime, it only sends notifications; For an audible alarm, consider our Siren Alarm
Low-Power Means Longer Battery Life: Because of the low power consumption, device batteries may last 5 years or more (depending on application and device usage/activity), on standard AAA Alkaline batteries (lithium batteries not required)!
From Simple to Super-Smart: After setting up your notification preferences, keep it simple and let the YoLink system do the rest and monitor your home and property for you. Or, utilize available advanced automation features, including 3rd-party integration with Alexa and IFTTT, to interact with other YoLink and 3rd-party smart devices. Limited only by your imagination!
Plug, Plug & Play! Plug Hub into an outlet, plug Hub into your router, scan in new devices, and enjoy your new system, in minutes! Your Hub is the only device that connects to the Internet, and a wired or WiFi connection is required (wired required for easy & fast Plug, Plug & Play, and most reliable and secure connection). WiFi connection set-up difficulty varies and requires changing settings to your network and/or your phone Changes to your network, passcodes, etc, require changes in the app.