The 604 is packaged in virtually the same case that their new DWL-900AP+ AirPlus Wireless Access Point [reviewed here] comes in. It's about the size of a stack of three CD "jewel cases", and has its status LEDs on the front panel, which are viewable from a wide range of top and front angles, and all connectors on the rear panel. The top of the cabinet is slightly sloped and not stacking-friendly, but has mounting features molded into the bottom, in case you wanted to wall-mount it. You get Link/Activity LEDs for each of the four LAN ports and single WAN port, and a Power light, too. D-Link throws in a normal UTP cable, printed Quick Installation Guide, CD with the PDF User Manual, and ZeroKnowledge bundle.
There's no support for uplink capability, so you'll need to depend on having it in whatever you use to expand the number of ports (if four aren't enough), or use a crossover cable. The 604 also doesn't support dialup modem or ISDN WAN connections, since it has only a 10BaseT Ethernet WAN connector.