SUNBELT BLADE-MOWER, 17", 5/8", NOTCH - B1DC1502 Replacement XHT Lawnmower blade. XHT(Xtreme Hardness & Toughness) blades are 25-40% harder than standard lawnmower blades. Benefits of the HXT blade are sharper and longer lasting cutting edges. More resistance to bending. Tighter tolerances in the aftermarket vs. OEM. XHT blades also offer greater impact toughness. (3) blades for 50" cut. Fits Toro models 718Z and Toro ZTR. Heavy Duty. Center Hole: 5/8" Length: 17" Thickness: .197 Type: High Lift - Notched Width: 2-1/2" This is an Aftermarket part. Thanks for looking!