Stumpjumper Brain thingy - lost grommet

sascos Posts: 100
edited February 2010 in MTB buying advice
Hi, the rear Brain valve thing on my Stumpjumper has the little rubber grommet missing from the top and I am concerned that dirt and moisture might get in?

Should I be concerned and/or does anyone know where I could get hold of a replacement grommet to fit?

Any help/advice welcome....thanks