My long haired cat Bell is prone to getting matts in his fur. The slicker brush (the one with the hundreds of little needle pointed bristles) didn't do squat but tick him off when it yanked on his hair. The metal comb wouldn't cut thru them. So basically I was resorting to having to cut them out, which was an adventure in itself because he isn't one to sit still for that kind of stuff. So a couple Saturdays ago I made a special trip to PetSmart to see if I could find a food for my recently passed cat Romeo that he would eat since he had up and stopped eating.
While walking around the store I come across the aisle that had the cat brushes and combs where I found what I needed for Bell's matted fur issue. I believe it's made by a company called Andis, it's a 9 blade dematting tool (pic should be on this post as an attachment if it doesn't show immediately). It has 9 curved teeth that are sharp on the inside of each "blade" and dull on the side that contacts the skin. At PetSmart I think it was like $16.99 but on eBay you can find it a couple dollars cheaper. Let me tell you this thing works amazing and cuts right through the matted fur like a hot knife through butter. And where it's a little tougher just kind of easily rotate your wrist back and forth a little as you pull and it glides through. I've been using it a little at a time and Bell doesn't mind it and I have gotten so much excess hair off of him, in maybe 4 uses I've dang near almost filled up a plastic grocery bag.
If you have a matted fur issue with your cat or even dog this thing is something to seriously consider purchasing.