Amazon.com: Linksys RE9000: AC3000 Tri-Band Wi-Fi Extender, Wireless Range Booster for Home, 4 Gigabit Ethernet Ports, Works with Any Wi-Fi Router (Black) : Everything Else
Linksys Official Support - Setting up the Linksys RE6500 and RE6500HG to Range Extender mode
Linksys Official Support - Configuring the Wireless Repeater mode on most Linksys Smart Wi-Fi Routers