USB active extension "Repeater" cable. 16 foot long extension cable. Up to five of these cables may be connected together to get to the maximum 80 foot length theoretically possible with USB. You cannot use regular, non-active extension cables past 16.4 feet (5 meters) without using hubs between the cables.
I've been told 5 metres is about the limit, unless you use powered hub thingies ( not sure with USB 2 ) - - -I know for a fact that my web camera DOES work with the 1.5 metre cable it came with plus a 5 metre extension cable - - - but NOT with another 5 metre cable added to that.