We bought one of these to keep the cats from crawling all over the car, particularly from smearing up the windshield with muddy paw prints. We just set it on the hood and it worked immediately to deter the cats; so well, if fact, that we have not had to buy additional batteries or canned air. You do feel a little silly when you accidently set it off yourself!

Pros: A good solution to our problem

Cons: Perhaps a little pricey

This sounds great, but how would you use it for keeping a dog off but allowing a cat on?

Pros: Keeping pets off furniture.

Cons: Dependability.