Mtd OEM Replacement Blade 335-677
FITS MODELS: 21'' mowers,1997 and newer 
Hi-lift blade 
Length 21'' (533.4mm)
Centre Hole Bow tie 
Outer Hole 5/16'' (7.9mm)
Centre 2 1/2'' (63.5mm)
Width 2 1/2'' (63.5mm)
Thickness .134'' (4.2mm)