Whats the purpose of this?

I know this part is plumbed into the fuel feed line just before the fuel rail, but what does it do? :scratch:
http://i808.photobucket.com/albums/z...x/55d49d5b.jpg

Hi mate,
I read its a pressure dampener and just smoothes out the flow of fuel.
I don't know if its recommended to use but I haven't got one.
Andy.

I've read the same, and it also stops the rail emptyin back to the tanks. Optional, but I use it.

Thanks guys, im binning it.::D

i bined mine to