Jokari Fizz Keeper Pump Bottle Cap

URL: http://www.jokari.com/products/gadgets.html
Does it work? Yup, yeah bubbles!

The science behind the product is hard to prove either way, but in my humble opinion it seems to work better than just the original cap. I was able to save multiple 2 liter bottles for 4-6 days, with almost no difference in taste and bubbles. (Some sodas seem to do better than others, wonder if it is the bottlers methods for adding carbonation to the liquid...)

A couple of rules to remember would be 1) don't shake the bottle while pumping (or anytime, it release the carbon dioxide from the liquid) 2) don't pump to hard or risk cracking the cap.
For comparison, I will also be trying the "Fizz Keeper Pump and Pour" in the coming weeks.