Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Perfect Tool

This thing is great! It is much easier to use than poking a hole with your keys and it creates a large opening in the can, almost as big as the mouth at the top. I've found it works best if you turn the can upside-down (and away from you) and apply pressure slowly, to prevent a big explosion when you pierce the can. The bottle opener and tab popper on thing thing also work fine, but the shotgun piercer is perfect!