The U1EXTT is to extend the distance between USB device and a host PC.The
  unit consists of a Master Unit and a Remote Unit,there is a standard Category-5
  Network cable connect these two units .The patended ASIC'S(Application
  Specific Intergrated Circuits)and other ic's are used to process and repeat
  USB signals.The master and remote units can be used separately by connecting a
  regular Cat-5/5e/6 Cable in any length (up to 150 feet).
   
 
  The maximum number of series Hubs in any USB connectionis five this
      includes any standard USB Hubs in the connection and the equivalent Hub
      rating of any Active U1EXTT
   
  Embedded USB Transceivers at both ends to prevent signal losss
   
  Using a high current USB devices with multiple U1EXTT might cause the host
      to supply over 500mA.
   
  The U1EXTT KIT does not support the USB 500uA maximum Suspend Current
      limit.if it is required then an external power supply must be used.
 
  U1EXTT-SI