Bio-Pak natural enzyme camper holding tank deodorizer and waste digester is simple to use and powerful. Just drop a single Bio-Pak into the holding tank and add water. The natural enzyme formula starts working immediately to control odor and break down solids in the waste tank. It also quickly liquefies paper, eliminating the need for special toilet paper. Completely safe for the environment and septic tanks. Continued use ensures that sensors, pipes, valves, and seals will be trouble-free and operational. 1 pack controls odor and treats waste in camper holding tank up to 40 gallon capacity. Fresh Scent.