Red plastic on flash.....?

Just a dumb question...

What is the red plastic on the lower part of most flashes that I see? Red eye reduction?

i think its focus assist. you probably have it on your g5 too...yanno, it paints a red orange circle on the subjects face before you take a shot with flash

It's the window for the AF assist beam.

^^^^^^ What they said. ^^^^^^

...but it's useless with the G-series cameras since it only works with the EOS cameras.

In the case of the EX flashs I thought it was the IR reciever/transmitter for useing them in a group, with a controller on the camera.

AFAIK it's optical not IR. I think this because even when the master flash is disabled it still fires in the visible region to control slave flashes.

The head of the flash itself contains the transmitter for slave units and the receiver is just below the head, just above the IR emitter.