I searched and couldn't find the answer. I bought an extra set of blades when I bought my mower, and another set yesterday. The first set were not FUSIONS, but the ones on my MINI and the ones I bought yesterday were. What's the difference? They look the same. I am no expert by any means, just wondering what the difference is, and if it's worth the small price difference? Also, I've cut with all three ( 2 set of FUSIONS, and 1 regular) and to be honest, can't tell any difference.