Pros: Cats learn quickly
This is a great training aid for any cats that gets into places where you do not want them. They learn quickly with a puff of air and a hiss scaring them. However, with my experience, my cat learned how this worked, and sneakily figured out how to get on my counters without setting it off, no matter where I put this! Also, if you have a small place, be prepared to get a puff of air aimed at you, if you should walk by it!