Instruct: Classify Amazon reviews into positive or negative sentiment
Query: de-matting blades way too dull to be effective

The de-matting blades are very dull; I want a comb where the blades have rounded tips but a blade surface that will slice through the matt like butter--these blades require you to hack and saw and pull, and even then it ends up just pulling the hairs (of my shrieking, writhing dog) out by the root, rather than slicing through the matt and leaving the hairs still attached to my dog. If I wanted to just grab the matt and rip it out by the roots, I could use a comb for that purpose. This tool is essentially useless on my Havanese dog's coat.