XHT BLADES Extreme Hardness Toughness 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 HEAVY DUTY XHT blades. Replaces the following OEM part numbers: KUBOTA K5617-34330 Center Hole: 11/16" Width: 2-1/2" Thickness: .250" Length: 18-1/2" HIGH LIFT Kubota MOWER DECK: RCK54-23ZG Kubota MOWER DECK: RCK54GR Kubota MOWER DECK: RCK54P-23BX **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.