DualComm Technology’s DCGS-2005 is a plug-and-play alternative to network taps. Port 1 is mirrored to port 1, 2, 3, 4, and 5 are all mirrored. This is a one-for-one copy of ports 2 and 3, 2 and 4, or 3 and 4 – you will not see any unicast traffic on port 5. This device is also different in that in that it requires a USB connection for power. The single USB power connection is the biggest disadvantage.”]
Source: https://taosecurity.blogspot.com/2010/09/dualcomm-port-mirroring-switch.html