A&I Aftermarket Equipment BLADE-MOWER, XHT, 19", 51/64" - A-B1JD1052 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. Center Hole: 51/64" Type: High Lift Where used: John Deere (UNDEFINED): SEVERAL (54") John Deere MOWER, RIDING: GT225 (54") John Deere MOWER, RIDING: GT235 (54") John Deere MOWER, RIDING: GT245 (54") John Deere MOWER, RIDING: GX255 (54") John Deere MOWER, RIDING: GX325 (54") John Deere MOWER, RIDING: GX335 (54") John Deere MOWER, RIDING: GX345 (54") John Deere MOWER, RIDING: GX355 (54") John Deere MOWER, RIDING: LX280 (54") John Deere MOWER, RIDING: LX288 (54") John Deere MOWER, RIDING: X320 (54") John Deere MOWER, RIDING: X340 (54") John Deere MOWER, RIDING: X360 (54") John Deere MOWER, RIDING: X465 (54") John Deere MOWER, RIDING: X475 (54") John Deere MOWER, RIDING: X485 (54") John Deere MOWER, RIDING: X495 (54") John Deere MOWER, RIDING: X500 (54") John Deere MOWER, RIDING: X520 (54") This is an Aftermarket A&I part.