My dad owns two Jack Russell Terriers, one with a broken coat and one with short hair. If you have ever owned a short haired dog, you know how much these type of dogs shed. And they shed little bitty short hairs. All over the place. Like on your floors, on your chairs and sofas, on your (or their) bed, and all over you!
I'd had enough of being covered in dog hair during my visits with my dad. I love his dogs, but I don't love looking like a dog myself. A friend who owns a lab had recommended this product. I purchased one for my dad and advised him to use it. He did, and you would not believe the hair that came off of those dogs! It was like another whole dog.
The product is pretty simple construction. It's a lot like those combs on the back of men's electric razors and it's attached to a plastic handle. It has close set tines that help remove the dogs undercoat without pulling on the fur. The hair is captured in the tines and you do have to occasionally remove the hair while you are combing the dog. My dad's larger dog seems to like it. The smaller dog has very ticklish skin so she kind of squirms while you are combing her. The price was a little high, but to remain dog hair free, it's worth it.