Maxpower 331981S 21-Inch Universal Gold Metal Mulching Lawn Mower Blade Universal Replacement for 21-inch Cut Mowers; Proudly Made in USA Commercial Gold Metal Mulching Blade with sharpened cutting teeth for a cleaner, finer cut Greater cutting surface for increased mulching Centrifugal air lift design for uniform chopping distribution 1-inch Center hole with reducing washers in the following sizes: 3/8-inch, 7/16-inch, 9/16-inch, 1/2-inch, 5/8-inch, and 13/16-inch