I have used a lot of different clippers for my dog (he is 10 years old). However, I have to say without a doubt that these are the best ones that I have purchased. I was able to clip my dog's nails easily and safely within a few minutes. They did not leave any splintering unlike many brands that I have used in the past. There is no guard! However, you honestly do not need a guard with these clippers. You can cut from both sides of the blade and never hit your dog's quick. They do work on any size dog (small or large). I love that I no longer have to make grooming appointments and spend $20 each time. I can easily trim my dog's nails in the privacy of our home when we have some extra free time.