If you buy your router based on the excitement of the packaging, you'll probably be passing Synology by, because this brown box is about as featureless as, well, a brown box.
The box contents aren't much more exciting, with just a LAN cable and power adapter inside.
Synology routers always have rather sober designs, too. The RT6600ax feels solid, though, with a thick plastic casting that looks like it will resist any knocks with ease. There are six built-in external antennas – four on the rear and two on the side.
Starting from the left, the port allocation begins with the USB 3.2 Gen 1 connection, which allows external storage or a printer to be connected for network access, as well as a mobile data dongle. Next along is the dedicated Gigabit Ethernet port for WAN connection to broadband. Then there is the four-port Gigabit hub for attaching devices with wired networking.
Look closer, however, and you will notice that the first port of the quartet is also labelled WAN 2 and 2.5Gbps, because it supports the higher bandwidth and can be enlisted to be a secondary WAN connection if you are connecting to a faster flavour of broadband or an extra Internet connection for resilience. Finally, there is a physical power button, a recessed reset button, and the connector for the power adapter.
One thing you don't get with this router, which previous Synology routers have offered, is a built-in SD card reader. Hardly essential, but it would have been nice to have nonetheless.
On the right-hand corner are two buttons for triggering WPS client setup, and toggling the WiFi radios if you want to turn them off while leaving the rest of the router active.
Seven lights on the top of the device near the front show status, including one for each LAN port, one for WAN, one for the WiFi radios, and a power LED.
Overall, this is a pretty standard physical specification, with the 2.5Gbps port and secondary WAN option the most unusual extras, and the USB a welcome inclusion too. However, the similarly-priced NETGEAR Nighthawk AX12 includes a four-port Gigabit Ethernet hub, with two ports that can be aggregated, a separate 5Gbps LAN port with WAN capability, and two USB ports.