The Quantum FreeXwire QLINK for Canon is a great way to create a mini-studio of Canon remote-controlled flashes. Take any number of Canon shoe-mount flashes, each fitted with a FreeXwire receiver and add a QLINK. Using your Quantum Pilot or TRIO flash on your camera as the master (controller), you can not only wirelessly trigger the flashes, but control their output from -3 stops to +2 stops. Alternately, you can set each flash to Auto and let the remote flash determine its own exposure.
Note: Requires a TRIO or Pilot flash and a FreeXwire receiver plus a QLINK for use.