Fabulous little tool! Very easy to use on my dog without scaring him. The motor is quiet on the low speed, and a bit louder on fast speed. I start out slow, then switch to high speed when he relaxes a bit, back to slow if he gets antsy. Mind you, restlessness is a pretty good sign you have gone as far down on the nail as is reasonable to go. My dog's nails are black, so it is very easy to trim too far, even with this tool. So trim a bit, check the tip of the nail, trim a bit more if necessary. Just don't get crazy and start grinding away without checking your progress, because, like traditional clippers, it is indeed possible to "quick" your pet (make him bleed) by nicking the tip of the nail blood vessel - I haven't done it yet, but I did come close once, so I know it is possible. This is true even with use of the nail guard. So, if you just go slow and use care, this tool is ingenious. I emphasize, use care -- if you over-trim (quick) your dog or cat, you may as well throw this tool away, because once they start to fear any tool, it is next to impossible to get them to let you use it on them. On the other hand, if you really want proper short nails, remember that the vein naturally recedes with a shortened nail, and grows longer with an untrimmed nail. So just trim a bit each week, and that quick will start to recede, and you will then be able to get the nail shorter. Whatever you do, do not expect to be able to transform 1-inch nails back to Westminster show length with a single trim, with this or any tool. Like anything, just use some common sense.