Instruct: Classify a given Amazon review into positive or negative sentiment.
Query: Win-win! Covenient and environmentally friendly!

Overall, I highly recommend this product.Pros:It's really nice not having to go out to the store to buy bottles of seltzer water anymoreChargers are cheap - buy bulk and you can get them for 40 cents each or lessNo added salt like the store containersReally nice to add to juice, less sugar and you can stop drinking soda easilyCons:The design of the top piece is ok, but you have to be careful. When you twist the nozzle on and off, make sure you twist using the spout instead of the dispensing button, or the button will probably break.I wish the bottle were easier to fill, the hole on the top could be a bit larger. Not a deal breaker though.