MaxPower's 331980B includes (1) universal gold metal commercial mulching blade for 20 in. cut mowers. This blade measures 20 in. L and 2-1/2 in. W with a 1 in. center hole. It includes a cover washer and 6 reducing washers in the following sizes: 3/8 in., 7/16 in., 9/16 in., 1/2 in., 5/8 in. and 3/16 in. This blade is designed to fit MOST 20" cut mowers. Recommended for gas powered mowers - not to be used with battery powered or electric mowers. 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 to meet or exceed OEM specifications.