This part is commonly Used on models:
30551 62in Side Discharge Mower, Groundsmaster 200 Series
30555 52in Side Discharge Mower, Groundsmaster 200, 3320 and 3280-D Series Traction Unit
30553 72in Side Discharge Mower, Groundsmaster 200 Series
30569 62in Guardian Recycler Mower, Groundsmaster 200 Series