It's a passthrough. Basically, it serves as a two port switch so that if you need to connect another device. I use it to connect my xbox to the HR22, and in turn the HR22 is connected by a really long cat5 to the rest of the network.
If it is cat6 then you got one hell of a deal for 50' of it. Now the best part about the switch is you can always add more devices without having to worry about running more cable. Worth the couple extra bucks IMO.
Linksys - EtherFast 5-Port 10/100 Workgroup Switch for $15 at Best Buy. Just thought i would bring it up in case anyone was interested. I'm sure it will go back up tomorrow being a new week.