Supreme Green is an environmentally friendly water-soluble packet that provides odor-fighting protection and powerful effervescent cleaning action. One Supreme Green packet treats a 40-gallon holding tank by cleaning the toilet bowl, breaking down solids in the holding tank, and eliminating unpleasant odors. This bonus pack includes 36 packets. Eliminates unpleasant odors Environmentally friendly formula 36 packets | Century Chemical Supreme Green RV Holding Tank Treatment, 36 packets