Rotary 12919 Mulch Blades, Pack of 2 Can be used in place of John Deere GX20249 and GX20433 mower blades Combines the "hump" found in traditional mulching blades with the airflow tooth design producing more airflow and smaller clippings 2 bolt mounting style Dimensions are: 21 27/64" length by 2 1/2" wide with center hole diameter of 43/64" Can be used for various 42" John Deere lawn tractors