The RJ45 only uses 2-pairs of the 4-pairs (except for some 1GB Ethernet configurations that do use all 4-pairs). These adaptors only utilize the "spare" pairs, so full duplex is still available. However, crosstalk can be a problem, but I don't know how prevalent it is. I could be worth a try, especially on a 10 Mbps setup. Peter ----------------------------------------------- The NoSpin Group [log in to unmask] > -----Original Message----- > well this gizmos don't really work all that well, you need > another on the > other end. It splits the 4 pairs in the network cable into 2 > lines of two > pairs and use one pairs for each connection. less > throughput, no full > duplex, and in my experience prone to causing strange > connectivity problems. The NOSPIN Group is now offering Free PC Tech support at our newest website: http://freepctech.com