The concave shaped carbide tip provides aggressive stump blasting action by chipping the stump bit by bit. Part of the secret of their performance is always having a sharp edge. These round carbide tipped teeth are 3 teeth in one. Just loosen the lock nut, turn the tooth, tighten and tear back into the stump. It takes only seconds to sharpen the tooth this way and the tooth can be rotated up to three times to provide renewed cutting performance. This gives you 3 times the wear, letting you tear into stumps 3 times longer. The tool holders are bolt on replaceable in case of damage makes servicing quick and easy without special tools and can even be done in the field.