If it's about extending the range of a Wi-Fi network, I recommend using a pair of AV500 or AV1200 capable HomePlugs, where one unit has Wi-Fi built in or with a Wi-Fi access point. The way these work is that the primary unit connects to the router providing the Internet connection and the second unit connects with the primary unit by sending data over the electrical wiring.
I have had little luck with Wi-Fi range extenders in the past as while they seem to work great at first, after a few days they tend to crash out or lose connectivity with the main Wi-Fi access point. I've seen this happen across multiple brands such as TP-Link, D-Link and Netgear including with other people.
Another significant issue with Wi-Fi range extenders is that they cut the bandwidth in half as everything is repeated back to the main access point over the existing Wi-Fi network. For comparison, a HomePlug or wired Ethernet based approach to bring Wi-Fi to another area can actually double the bandwidth as each Wi-Fi access point can operate on independent channel numbers. For example, a set-top box streaming in the area with the second Wi-Fi access point will not consume any bandwidth provided by the main access point, although obviously the overall bandwidth is physically limited by the main Internet connection.