On Networks N300RE User Manual - Manual (Page 11)

Getting Started
11
N300RE WiFi Range Extender
The extender detects wireless networks and displays a list.
2. Either select a network from the list, or select the Manually input my wireless SSID radio
button and type the SSID.
3. Click Continue.
4. Enter the passphrase for your wireless network and click Continue.
The extender wireless network name (SSID) changes to the name of your wireless
network name with _EXT added to the end.
5. (Optional) In the Name (SSID) field, type a different name for the extender network.
6. Click Continue.
The extender connects to your existing WiFi network.