You tell me what this is?

http://www.youtube.com/watch%3Fv%3Den9CoYb0OHs


Compair to this video...
http://www.youtube.com/watch?v=jgxW9M_B ... r_embedded

Then this with the cap? or what ever it is...the flow looks much worst then with out it...
http://www.youtube.com/watch?v=O-rJH9xB7fk&feature=fvw