CERRIXIAN RJ45 Surge Arrester for NICs, Terminations, Hubs, MAUs and Other Ethernet Devices（D）

Whenever a computer is plugged into this the connection becomes unstable and the speed is reduced to about 0.1Mbps. There doesn't appear to be the option to get support from the seller and we have used the item now and wired it into the ground so it's too late to return it.