Stens 330-501 PK3 Hi-Lift Blades - 21" Heavy Duty Stens 330 501 Hi Lift Blade 3 Pack John Deere TCU15881 Replaces OEM John Deere M128485 M131958 M144196 M163983 TCU15881 Fits Models John Deere 737 757 777 797 997 and 7 Iron Requires 3 for 60 Inch deck Specs Length 21 Inch Center Hole 7/8 Inch Width 3 Inch Thickness .250 Inch