Tips for Heavily Oxidized Aluminum. First of all, determine the extent of oxidation on the aluminum surface. If it is determined that the surface is in relatively good shape, i.e. light oxidation, then skip this step and move on to polishing with Flitz.
Q1: How long of a cable can I use to connect my device? A1: In practice, the USB specification limits the length of a cable between full speed devices to 5 meters (a little under 16 feet 5 inches). For a low speed device the limit is 3 meters (9 feet 10 inches).
5m is the limitation of USB cable if I remember correctly, check USB-IF for more information. However, if you cascade hubs with 5m USB cables, this will allow you to connect a device 30m away with 5 hubs daisy chain. I might be wrong, it's probably 30ft or 30m. do check the spec though.