I have a semi-long haired cat whose fur has the ability to knot, seemingly overnight. No amount of gentle tugging with a brush could get the matted knots out without a good deal of yowling and the odd scratch being exchanged. This was a stressful situation for both cat and human. I tried various brushes and even bought the Furminator (daft name), which had tremendous reviews. Nothing really worked and I felt that the Furminator was heavy and a bit harsh as it dragged its way through the cat's fur. Finally, I tried this little gadget and I am delighted to report that it appears to be perfect. With very little tugging, the knots loosened and came out relatively easily and without the usual yowling protestation. In fact, the cat seems to rather like the feeling of this little brush and she purrs happily while I groom her, flopping from side to side to ensure that both sides are properly combed. I recommend this to anyone with a short- to semi-long haired cat. It's gentle and it works.