XHT BLADES Extreme Hardness Toughness MADE IN THE USA!!! 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. By the way they are made in the USA! Hands down the ABSOLUTE best aftermarket replacement blade on the market! This sale is for 3 replacement XHT blades. SUPER HIGH LIFTS. You don't need 1 super high lift and 2 regular high lifts but you can replace with this set which all three are the super high lifts and will work perfectly. Replaces the following OEM part numbers: SIMPLICITY: 1704100 1704100AS 1704100SM 1716696A 1716696ASM 3 needed on 44" cut decks. Center Hole: 3/4" Width: 2" Thickness: .197" Length: 16-1/8" Outside hole: 13/32" Center to Center on outside holes: 2-9/16" **DISCLAIMER- WE LIST BLADE PART NUMBERS, MODEL NUMBERS AND DIMENSIONS FOR REFERENCES BUT IT IS UP TO YOU TO BUY THE RIGHT BLADES. If you order them and they don't fit it is not our fault! We always accept returns but the shipping to and from will be your responsibility unless we make the error.