Radxa produces many single-board computers (SBCs) in the pursuit of usurpring the more popular Raspberry Pi ecoysystem. For example, the company often even borrows from Raspberry Pi's naming scheme with some of its devices like the Rock 5B Plus and the Rock 5T (curr. $226.99 on Amazon).
Now, the company has released an add-on board designed to expand the versatility of the Raspberry Pi 5 itself. As its name suggests, the Dual 2.5G Router HAT brings a pair of 2.5 Gigabit Ethernet ports to the Raspberry Pi 5 via the SBC's 40-pin GPIO header. For reference, these ports leverage the Realtek RTL8125B controller rather than MediaTek or Intel equivalents.
Also the new release contains an M Key slot for adding an M.2 2280 SSD. According to Radxa, SSDs can run at up to PCIe 3.0 x1 speeds over an IPEX connector. For some reason, while the company advertises the HAT as using FPC instead, it bundles an IPEX to FPC adapter in the box. As the images below show, the HAT ships with screws and standoffs, as well as a heatsink to prevent thermal throttling.
Currently, the Radxa Dual 2.5G Router HAT is available to purchase from AliExpress for approximately $40. Alternatively, the HAT can be picked up from Arace Tech for about the same price. Please see Radxa's wiki for more details.
Source(s)
AliExpress, Arace Tech, Radxa via CNX Software & Liliputing