XHT 20", 5/8" Mower Blade (Set of 11) - B1TR3107,11 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. (11) blades for 16' deck Groundsmaster. Fits Toro 580D mower. Center Hole 5/8" Length 20" Thickness .250 Type Medium Lift Width 2-1/2" Crossed From: TOR-5156 J. THOMAS TOR5156 J. THOMAS TO20A MOW MORE 050657 LESCO 231024 LANDSCAPE SUPPLY 345-156 STENS 345156 STENS 6270 ROTARY 69-6920 TORO / WHEEL HORSE 69-6920-03 TORO / WHEEL HORSE 696920 TORO / WHEEL HORSE 69692003 TORO / WHEEL HORSE 7-06790 PRIME LINE 706790 PRIME LINE 91768 LASER SALES 94-029 OREGON 94-920 OREGON 94029 OREGON 94920 OREGON A physical address must be provided, NO P.O. BOXES. Thanks for looking!