IMPORTANT: This router has been flashed with custom firmware and is being sold specifically for use with OpenWrt. Do not purchase if you need the original Belkin factory firmware.
Belkin RT3200 WiFi 6 Router running OpenWrt 25.12.5.
Specs:

• Dual-band WiFi 6 (802.11ax)
• 4×4 MIMO on both 2.4 GHz and 5 GHz
• AX3200-class wireless
• 5× Gigabit Ethernet ports (1 WAN + 4 LAN)
• 512 MB RAM
• 128 MB NAND flash
• 1× USB 2.0 port
• MediaTek MT7622BV dual-core 1.35 GHz CPU
• OpenWrt support with full VLAN functionality

Purchased new in October 2023. Works great and is in excellent condition. Comes with the original box, power supply, and Ethernet cable.
Flash Layout:
This unit has been converted to the UBI flash layout and is intended to run OpenWrt permanently. Returning to OEM firmware is not recommended due to the risk of bricking the device.
See the OpenWrt Wiki for more information. It's listed under the Linksys E8450, as both models share the same internal hardware.