Flextrodes are a unique EEG sensor placement system that uses special fittings to hold gold disks inside a felt-lined compartment.  These are held on the head using velcro strips.  The Flextrode system is patented (US Patent #6,574,513)

Additional information can be found at:

http://www.brainmaster.com/productinfo/flextrodes/flextrodes.html

 

There are also helpful videos at:

http://www.youtube.com/watch?v=cryS60RGJWE

http://www.youtube.com/watch?v=x5D6wxA7QVc