MaxPower's 331981S 21" Universal Gold Metal Commercial Mulching Blade includes a cover washer and 6 reducing washers in the following sizes: 3/8", 7/16", 9/16", 1/2", 5/8", and 13/16". This blade measures 21" long by 2-1/2" wide with a 1” center hole. Commercial mulching blades feature greater cutting surface for increased mulching performance, sharpened cutting teeth for a precision cut, and a centrifugal air lift design for uniform chopping distribution. MaxPower blades are proudly manufactured in the USA to meet or exceed OEM specifications.