In terms of connectivity, you will need:
- Wi-Fi 802.11 b/g/n,
- WEP/WPA/WPA2-personal security
- Bluetooth Smart Ready (Bluetooth 4.0) iOS device
https://support.withings.com/hc/zh-cn/sections/6216371591569-Smart-Kid-Scale
https://support.withings.com/hc/zh-cn/sections/200537908-FAQ