I found the people clippers didn't last very long, at least those purchased at Walmart. I finally broke down and got some good ones at an animal supply. They cost a lot, but have lasted years and years with just some replacement blades.
I use
Discount Pet Supplies, Pet Supply, Online Pet Supplies and
Pet Supplies | Dog & Cat Supplies | Vaccines | Revival Animal Health for a lot of my supplies.
I use 2 different clippers. I use a small clipper with the teeth tight together for ears and bums to avoid cutting an ear. I have used mustache groomers, but I prefer Oster finishing clipper for the ears and bums. The teeth in the blades are very close together.