TP-Link TL-WA701ND User Manual page 13

TL-WA701ND/TL-WA801ND/TL-WA901ND Wireless N Access Point User Guide
 Used as WPS button:
If you have client devices, such as wireless adapters, that support Wi-Fi Protected Setup,
then you can press this button to quickly establish a connection between the Access Point
and client devices and automatically configure wireless security for your wireless network.
Wireless antenna: The external antenna is used to transmit and receive wireless data.
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