Other reviewers said the blade was not an exact fit.  In my case it was a drop-in; maybe because I already had switched over or maybe I just happen to have the right kind of Edge Hog.  Anyway, I bought 2, put one in, and had a grand time ripping trenches along the concrete walk and driveway.  Oh, I held the old one up to it and I gained about an inch with the new blade.