Seriously now, why? Imagine you are a cat or a dog and someone comes at you with this thing that spins and makes noise, and they are trying to put your toes into it? You know what I am talking about, those NEW fangled pet claw filers that are sold everywhere now; Pet-paws or Petty-Paws. They are even on the inter- net. Don't get me wrong, I think who ever invented them had a great idea, but they obviously had never worked in the Veterinary field, or tried to cut the nails on a fractious cat. For God sake, my dog runs when I hold a spoon down to her. If an animal is afraid there is no way you will be able to get close enough to him to use it. If your animal were to jump whilst his digits where in the roto, you could zip off a lot more than you bargained for. The so called safety stop or shield on these devises is "one size fits all" and with animals that is not the case. You could do major damage to a kittens paw before his little pads hit the shield. I can see using this device on an old dog, who would let a child dress him in her favorite doll clothes, or one who is used to being groomed regularly, but I don't think it is ideal for your every day feline or jumpy puppy!
Having worked and lived in the animal industry in some capacity for a greater part of my life I would recommend a good pair of Veterinary type nail clippers. A large pair of ordinary human toe nail clippers will also do the trick on cats and kittens. If your cat or dog is the least bit squirmy however, I highly recommend having their nails trimmed professionally. If you have other small pets, like rabbits or guinea pigs please do not try to cut their nails by yourself. These small animals are especially fragile and a well intentioned owner could easily do them harm. However you plan to keep your pets nails trimmed, start at an early age and cut them regularly to keep them safe and unafraid of the process. Call your Veterinarians office. Most of them will offer to cut your pets nails for a small fee without charging you for an office visit.
I am not trying to bash the makers, just protect the safety of our pets and furry family members.