CopperHead Mulching Blade replaces John Deere M170642, 21-3/8" X .187" X 2-1/2" X .800" Ctr Hole. Fits: X330, X350, X370, X354, X380 Z335E, Z335M, Z345M, Z345R 42" Accel Deep Fits: X330, X350, X370, X354, X380 Z335E, Z335M, Z345M, Z345R.Replaces:JOHN...