OpenWRT firmware flashing in Mi 4A Gigabit WiFi Router - Lazy Tourer
DD-WRT vs. OpenWrt: Which open-source router firmware should you pick?
OpenWrt Wiki] Xiaomi Mi Router 3 Pro (R3P)
Amazon.com: GL.iNet GL-MT1300 (Beryl) VPN Wireless Little Travel Router – Connect to Hotel WiFi & Captive Portal, USB 3.0, 3 Gigabit Ports, Range Extender, Assess Point, Pocket-Sized, MicroSD Slot, Easy to Setup :