ThunderShirts use gentle hugging pressure to calm your cat. The gentle, constant pressure has a calming effect for most cats if they are anxious, fearful or overexcited. Thundershirts have now helped thousands of cats around the world who suffer from anxiety. ThunderShirts are rapidly being embraced by professionals; thousands of veterinarians are now recommending the Thundershirt for cats who suffer from anxiety. Experts believe that pressure has a calming effect on the nervous system, possibly by releasing a calming hormone like endorphins. It's a safe and drug free solution for your cat's anxiety, and with a Money Back Guarantee how can you say no?