A&I XHT 21", 7/8", ML Mower Blade - B1JD1040 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 60" cut. Fits 7 Iron deck, Z Trak, F620, M665, F680 models. Also fits 4200, 4300 and 4400 compact utility tractors. Center Hole 7/8" Length 21" Thickness .312 Type Medium Lift Width 2-1/2" Crossed From: M128485 JOHN DEERE M131958 JOHN DEERE M96730 SHOUP M96742 SHOUP 330-501 STENS 330-591 STENS 330501 STENS 330591 STENS 50-3035 WINDSOR 503035 WINDSOR 6479 ROTARY 7-06797 PRIME LINE 706797 PRIME LINE 91-078 OREGON 91078 OREGON 91668 LASER SALES This is an aftermarket product, not an OEM. A physical address must be provided, NO P.O. BOXES. Thanks for looking!