Hyper .21 Booster Attachment....
 

Anyone know what, how, & if this thing works?
I can get one for $44.81, So it must do something.

EDIT: The seller says: "This fits to your hyper .21 4 or 8 port engine. It acts like a turbo on your car and increases compression in the engine."

http://i14.ebayimg.com/03/i/02/75/02/3e_1_b.JPG

It's a boost bottle. I bought a GS boost bottle for my Hyper .21. No idea if it did anything as I changed my clutch bell, my gas choice, and put the boost bottle on at the same time. It doesn't look quite as neat as that one does but the one from GS was $12 Canadian. So probably $10 US.