"My golden retriever has thick, matted, knotted hair. Even when washed and brushed with an undercoat brush, these clippers could not do the job. First of all the plastic attachments kept popping off & Second, the motor kept bogging down on me and the clippers would stop all together. After about 1 hour with only the easy top side done the clippers quit for good. I can see these maybe working well on a consistantly groomed dog, but not for a long, thick haired, forest rolling, puddle jumping dirty ole dog... No matter how much pre washing and grooming you do."