I know I'm going to get flamed with replys of disbelief but this is the truth. My dealer told me to try Hustlers new Fusion blades for my Super Z and I bought a new set on June 9th, 2005. Today, July 20, I sharpened them for the first time. And guess what? They really didn't need to be sharpened! By my estimate these blades have cut well over 350 lawns of 1/4 to 1/2 acre in size since June 9th. These things are unbelievable. I mow nothing but irrigated St Augustine turf so that explains some of the longevety. My dealer told me the other day that maybe he shouldn't sell them anymore for fear of loosing repeat blade business. Keep up the good work Hustler!