By adding the Toro Recycler system to your Toro GrandStand riding mower, you create your own natural fertilizer. The 40 in. Recycler Kit, when installed on compatible 40 in. deck Toro zero turn riding mowers, gives it the capability to mulch grass by cutting it multiple times turning it into fine clipping pieces. These are returned under the mower back into the soil to serve as natural fertilizer.